enVision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers

Practice with the help of enVision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers regularly and improve your accuracy in solving questions.

enVision Math Common Core 2nd Grade Answers Key Topic 1 Understand Multiplication and Division of Whole Numbers

Essential Question: How can thinking about equal groups help you understand the connection between multiplication and division?
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 1

enVision STEM Project: Forming Groups
Do Research Many types of animals form groups. Use the Internet or other sources to discover which animals form groups. Why do they do this? What are the benefits for these animals of being in a group?
Journal: Write a Report Include what you found. Also in your report:

  • Draw representations of animals in equal groups. Give a reason why those animals formed groups.
  • Use a multiplication equation to show the total number of animals. Use a division equation to show the number of animals in each group.

Review What You Know

• add
• subtract
• skip count
• ones

Vocabulary

Choose the best term from the box. Write it on the blank.

Question 1.
If you combine different sized groups to find how many in all, you ___.

Answer:
To find how many in all we can use the term add.

Explanation:
In the above-given question,
given that,
choose the best term from the box.
In the box, they gave the four words.
they are added, subtract, skip count, and ones.
so I am choosing the term to add.
the meaning of combine is to add.
example:
In group A there are 3 rats.
In group B there are 4 rats.
so to find how many rats are there in two groups?
we will use the term add.
3 + 4 = 7.

Question 2.
___ are groups of single objects.

Answer:
Ones are groups of single objects.

Explanation:
In the above-given question,
given that,
choose the best term from the box.
In the box, they gave the four words.
they are added, subtract, skip count, and ones.
so I am choosing the term ones.
example:
if there is a rat in group A.
we will say that there is only one rat.
so we will use the term ones for a single object.

Question 3.
When you say the numbers 5, 10, 15, 20, you ___.

Answer:
We use the term skip count when the numbers are skipping by 5.

Explanation:
In the above-given question,
given that,
choose the best term from the box.
In the box, they gave the four words.
they are added, subtract, skip count, and ones.
so I am choosing the word skip count.
example:
if they gave the numbers 5, 10, 15, and 20.
we will say that the numbers are skipping by 5.
so we will use the term skip count.

Adding
Find each sum.

Question 4.
5 + 5 + 5 = ?

Answer:
5 + 5 + 5 = 15.

Explanation:
In the above-given question,
given that,
find the sum of numbers.
5 + 5 + 5.
5 + 5 = 10.
10 + 5 = 15.
so 5 + 5 + 5 = 15.

Question 5.
7 + 7 = ?

Answer:
7 + 7 = 14.

Explanation:
In the above-given question,
given that,
find the sum of numbers.
7 + 7.
7 + 7 = 14.
so 7 + 7 = 14.

Question 6.
3 + 3 + 3 = ?

Answer:
3 + 3 + 3 = 9.

Explanation:
In the above-given question,
given that,
find the sum of numbers.
3 + 3 + 3.
3 + 3 = 6.
6 + 3 = 9.
so 3 + 3 + 3 = 9.

Question 7.
2 + 2 + 2 + 2 = ?

Answer:
2 + 2 + 2 + 2 = 8.

Explanation:
In the above-given question,
given that,
find the sum of numbers.
2 + 2 + 2 + 2.
2 + 2 = 4.
4 + 2 = 6.
6 + 2 = 8.
so 2 + 2 + 2 + 2 = 8.

Question 8.
6 + 6 + 6 = ?

Answer:
6 + 6 + 6 = 18.

Explanation:
In the above-given question,
given that,
find the sum of numbers.
6 + 6 + 6.
6 + 6 = 12.
12 + 6 = 18.
so 6 + 6 + 6 = 8.

Question 9.
9 + 9 + 9 = ?

Answer:
9 + 9 + 9 = 27.

Explanation:
In the above-given question,
given that,
find the sum of numbers.
9 + 9 + 9.
9 + 9 = 18.
18 + 9 = 27.
so 9 + 9 + 9 = 27.

Subtracting
Find each difference.

Question 10.
21 – 7 = ?
14 – 7 = ?
7 – 7 = ?

Answer:
21 – 7 = 14.
14 – 7 = 7.
7 – 7 = 0.

Explanation:
In the above-given question,
given that,
find the difference of two numbers.
21 – 7 = 14.
14 – 7 = 7.
7 – 7 = 0.
In the given question the numbers are increasing by 7.
0 + 7 = 7.
7 + 7 = 14.
14 + 7 = 21.

Question 11.
15 – 5 = ?
10 – 5 = ?
5 – 5= ?

Answer:
15 – 5 = 10.
10 – 5 = 5.
5 – 5 = 0.

Explanation:
In the above-given question,
given that,
find the difference of two numbers.
15 – 5 = 10.
10 – 5 = 5.
5 – 5 = 0.
In the given question, the numbers are increasing by 5.
0 + 5 = 5.
5 + 5 = 10.
10 + 5 = 15.

Question 12.
27 – 9 = ?
18 – 9 = ?
9 – 9 = ?

Answer:
27 – 9 = 18.
18 – 9 = 9.
9 – 9 = 0.

Explanation:
In the above-given question,
given that,
find the difference of two numbers.
27 – 9 = 18.
18 – 9 = 9.
9 – 9 = 0.
In the given question, the numbers are increasing by 9.
0 + 9 = 9.
9 + 9 = 18.
18 + 9 = 27.

Skip Counting on the Number Line

Question 13.
If you continue skip counting using the same pattern, what will be the next number?
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 1.1
A. 8
B. 10
C. 12
D. 14

Answer:
The next number will be 8.

Explanation:
In the above-given figure,
given that,
In the number line, there are 12 numbers.
the numbers are increasing by 2.
that means they are skipping by 2.
0 + 2 = 2.
2 + 2 = 4.
4 + 2 = 6.
6 + 2 = 8.
so the next number is 8.

Pick a project

PROJECT 1A
What is the tallest building in Florida?
Project: Construct a Tall Building
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 3.5

Answer:
The tallest building in Florida is Panorama tower.

Explanation:
In the above-given question,
given that,
what is the tallest building in Florida?
The tallest building in Panorama Tower.
the height of the building is 868 m.
it is about 265 feet.
it has almost 85 floors.
so panorama tower is the tallest building.

PROJECT 1B
Would you like to travel to another planet?
Project: Build a Space Probe
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 3.6

PROJECT 1C
What are some places where you would like to live?
Project: Draw a Neighborhood
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 3.7

Answer:
Some places would I like to live in Goa, Kerela, and Konaseema.

Explanation:
In the above-given question,
given that,
write some of the places would you like to live.
so I liked living in goa because it is very near to the sea.
goa is the smallest state.
I liked living in Kerela because it looks very beautiful.
it is famous for tea plantations and also backwater.
It rains every day.
I like to live in Kona Seema because it looks like greenery.
It is famous for coconut plants and also for temples.

3-ACT MATH PREVIEW

Math Modeling

What’s the point?

Before watching the video, think:
I do a lot of my writing on a laptop or a tablet. When do you prefer to use a pencil? How about crayons, pens, and colored pencils? You probably own plenty of different writing tools. You can even find some interesting ways to use them.
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 3.8

Answer:
We will use a pencil to paint.

Explanation:
In the above-given question,
given that,
when you will use the pencil on a laptop or tablet?
we will use the pencil for drawing figures in paint.

Lesson 1.1 Relate Multiplication and Addition

Activity

Solve & Share

Ms. Witt bought 4 boxes of paint with 5 jars of paint in each box. Ms. Karp bought 3 boxes of paint with 6 jars in each box. Who bought more jars of paint? How many more?
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 3.9

Look Back!
How can you use counters and addition equations to help solve the problems?

Answer:
Ms. Witt bought 2 more jars of paint.

Explanation:
In the above-given question,
given that,
Ms. Witt bought 4 jars of paint with 5 jars of paint in each box.
4 x 5 = 20.
5 + 5 + 5 + 5 = 20.
Ms. Karp bought 3 boxes of paint with 6 jars in each box.
3 x 6 = 18.
3 + 3 + 3 + 3 + 3 + 3 = 18.
20 – 18 = 2.
so Ms. Witt bought two more jars of paint.

Essential Question
How can you find the total number of objects in equal groups?

Visual Learning Bridge

A
Jessie used 3 bags to bring home the goldfish she won at the Fun Fair. She put the same number of goldfish in each bag. How many goldfish did she win?
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 3.9

Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 4.2

Convince Me!
Model with Math Suppose Jessie won 5 bags of 8 goldfish. Use math you know to represent the problem and find the number of goldfish Jessie won.

Answer:
The number of goldfish Jessie won = 40.

Explanation:
In the above-given question,
given that,
suppose Jessie won 5 bags of 8 goldfish.
8 + 8 + 8 + 8 + 8.
8 + 8 = 16.
16 + 8 = 24.
24 + 8 = 32.
32 + 8 = 40.
5 x 8 = 40.
so the number of goldfish Jessie won = 40.

Guided Practice

Do You Understand?

Question 1.
Can you write 5 + 5 + 5 + 5 = 20 as a multiplication equation? Explain.

Answer:
Yes, we can write the multiplication equation.

Explanation:
In the above-given question,
given that,
the addition equation is 5 + 5 + 5 + 5 = 20.
The multiplication equation is:
4 x 5 = 20.
so we can write the multiplication equation.

Question 2.
Can you write 3 + 4+ 7 = 14 as a multiplication equation? Explain.

Answer:
Yes, we can write the multiplication equation.

Explanation:
In the above-given question,
given that,
the addition equation is 3 + 4 + 7 = 14.
3 + 4 = 7.
The multiplication equation is:
2 x 7 = 14.
so we can write the multiplication equation.

Question 3.
Jessie buys 4 packages of stones. There are 6 stones in each package. How many stones does Jessie buy?
Use counters to represent the problem. Then write an addition equation and a multiplication equation to solve.

Answer:
Addition equation = 6 + 6 + 6 + 6 = 24.
Multiplication equation = 4 x 6 = 24.

Explanation:
In the above-given question,
given that,
Jessie buys 4 packages of stones.
There are 6 stones in each package.
6 + 6 + 6 + 6 = 24.
4 x 6 = 24.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-1
Do You Know How?

Complete 4 and 5. Use the pictures to help.

Question 4.
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 5.1
2 groups of ___
4 + 4 = ___
2 × __ = ___

Answer:
2 groups of 4.
4 + 4 = 8.
2 x 4 = 8.

Explanation:
In the above-given question,
given that,
there are 2 groups of 4.
that means group A contains 4.
group B contains 4.
addition equation is 4 + 4 = 8.
multiplication equation is 2 x 4 = 8.

Question 5.
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 5.2
____ groups of 6
6 + ___ + ___ = ___
3 × __ = __

Answer:
3 groups of 6.
6 + 6 + 6 = 18.
3 x 6 = 18.

Explanation:
In the above-given question,
given that,
there are 3 groups of 6.
that means group A contains 6.
group B contains 6.
group C contains 6.
addition equation is 6 + 6 + 6 = 18.
multiplication equation is 3 x 6 = 18.

Independent Practice
Leveled Practice Complete 6 and 7. Use the pictures to help.

Question 6.
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 5.3
2 groups of ___
5 + ___ = ___
2 × ___ = ___

Answer:
2 groupsof 5.
5 + 5 = 10.
2 x 5 = 10.

Explanation:
In the above-given question,
given that,
there are 2 groups of 5.
that means group A contains 5.
group B contains 5.
addition equation is 5 + 5 = 10.
multiplication equation is 2 x 5 = 10.

Question 7.
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 5.4
5 groups of ___
4 + 4 + 4 + __ + ___ = ___
5 × __ = ___

Answer:
5 groups of 4.
4 + 4 + 4 + 4 + 4 = 20.
5 x 4 = 20.

Explanation:
In the above-given question,
given that,
there are 5 groups of 4.
that means group A contains 4.
group B contains 4.
group C contains 4.
group D contains 4.
group E contains 4.
addition equation is 4 + 4 + 4 + 4 + 4 = 20.
multiplication equation is 5 x 4 = 20.

In 8-11, complete each equation. Use counters or draw a picture to help.

Question 8.
8 + 8 + 8 + 8 = 4 × __

Answer:
4 groups of 8.
8 + 8 + 8 + 8 = 32.
4 x 8 = 32.

Explanation:
In the above-given question,
given that,
there are 4 groups of 8.
that means group A contains 8.
group B contains 8.
group C contains 8.
group D contains 8.
addition equation is 8 + 8 + 8 + 8 = 32.
multiplication equation is 4 x 8 = 32.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-2

Question 9.
__ + __ + __ = 3 × 7

Answer:
3 groups of 7.
7 + 7 + 7 = 21.
3 x 7 = 21.

Explanation:
In the above-given question,
given that,
there are 3 groups of 7.
that means group A contains 7.
group B contains 7.
group C contains 7.
addition equation is 7 + 7 + 7 = 21.
multiplication equation is 3 x 7 = 21.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-3

Question 10.
9 + __ + __ = 3 × ___

Answer:
3 groups of 9.
9 + 9 + 9 = 27.
3 x 9 = 27.

Explanation:
In the above-given question,
given that,
there are 3 groups of 9.
that means group A contains 9.
group B contains 9.
group C contains 9.
addition equation is 9 + 9 + 9 = 27.
multiplication equation is 3 x 9 = 27.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-4

Question 11.
6 + 6 + 6 + 6 + 6 = ___ × ___

Answer:
5 groups of 6.
6 + 6 + 6 + 6 + 6 = 30.
5 x 6 = 30.

Explanation:
In the above-given question,
given that,
there are 5 groups of 6.
that means group A contains 6.
group B contains 6.
group C contains 6.
group D contains 6.
group E contains 6.
addition equation is 6 + 6 + 6 + 6 + 6 = 30.
multiplication equation is 5 x 6 = 30.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-5

Problem Solving

Question 12.
Debra draws this shape on the back of her notebook.
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 6.1
What is the name of the shape Debra draws? How do you know?

Answer:
The name of the shape Debra draws is a hexagon.

Explanation:
In the above-given question,
given that,
Debra shows the shape on the back of her notebook.
For example: if the shape contains 3 sides it is a triangle.
if the shape contains 4 sides it is a rhombus.
if the shape contains 5 sides it is a pentagon.
if the shape contains 6 sides it is the hexagon.
so the above-drawn figure is a hexagon.
It has 6 sides.

Question 13.
Model with Math Salvatore gets 50 trading cards for his birthday. He gives 22 cards to Madison, and Madison gives 18 cards to Salvatore. Then Salvatore’s sister gives him 14 cards. How many trading cards does Salvatore have now? Use math to represent the problem.

Answer:
The number of cards does Salvatore has = 60 cards.

Explanation:
In the above-given question,
given that,
Salvatore gets 50 trading cards for his birthday.
he gives 22 cards to madison, and madison gives 18 cards to Salvatore.
then Salvatore’s sister gives him 14 cards.
50 – 22 = 28.
28 + 18 = 46.
46 + 14 = 60.
so the number of cards does Salvatore have = 60.

Question 14.
Higher Order Thinking Luke says you can always add and you can always multiply to join groups. Is he correct? Explain why or why not.

Answer:
Yes, Luke was correct.

Explanation:
In the above-given question,
given that,
Luke says you can always add and you can always multiply to join groups.
for example:
2 groups of 5.
5 + 5 = 10.
2 x 5 = 10.
so luke was correct.

Question 15.
Lois says any addition equation where the addends are all the same can be written as a multiplication equation. Is Lois correct? Explain why or why not.

Answer:
Yes, Lois was correct.

Explanation:
In the above-given question,
given that,
Lois says any addition equation where the addends are all the same can be written as a multiplication equation.
for example 3 groups of 4.
4 + 4 + 4 = 12.
3 x 4 = 12.
so Lois was correct.

Assessment Practice

Question 16.
Tom has 12 ears of field corn to make table decorations. He arranges them in equal groups. Which sentences could Tom use to describe his groups? Select all that are correct.
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 7 Tom arranged 2 groups of 4 ears.
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 7 Tom arranged 4 groups of 2 ears.
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 7 Tom arranged 6 groups of 2 ears.
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 7 Tom arranged 3 groups of 4 ears.
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 7 Tom arranged 1 group of 10 ears.

Answer:
Tom arranged 6 groups of 2 ears.
he arranged 3 groups of 4 ears.

Explanation:
In the above-given question,
given that,
Tom has 12 years of field corn to make table decorations.
He arranges them in equal groups.
Addition equation:
6 groups of 2 ears.
2 + 2 + 2 + 2 + 2 + 2 = 12.
multiplication equation:
6 x 2 = 12.
3 groups of 4 ears.
4 + 4 + 4 = 12.
3 x 4 = 12.

Question 17.
Jenna has 24 flowers. She arranges them in vases with an equal number of flowers in each vase. Which sentences could Jenna use to describe her flowers? Select all that are correct.
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 8 Jenna arranged 4 flowers in each of 6 vases.
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 8 Jenna arranged 3 flowers in each of 9 vases.
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 8 Jenna arranged 5 flowers in each of 5 vases.
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 8 Jenna arranged 6 flowers in each of 3 vases.
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 8 Jenna arranged 8 flowers in each of 3 vases.

Answer:
Jenna arranged 4 flowers in each of 6 vases.
she also arranged 8 flowers in each of the 3 vases.

Explanation:
In the above-given question,
given that,
Jenna has 24 flowers.
she arranges them in vases with an equal number of flowers in each vase.
Jenna arranged 4 flowers in each of 6 vases.
4 flowers of 6 vases.
6 + 6 + 6 + 6 = 24.
4 x 6 = 24.
she also arranged 8 flowers in each of 3 vases.
8 flowers of 3 vases.
3 + 3 + 3 + 3 + 3 + 3 + 3 + 3 = 24.
8 x 3 = 24.

Lesson 1.2 Multiplication on the Number Line

Activity

Solve & Share

Harvey the Hop Toad starts at 0 and jumps 7 times in the same direction. Each time he jumps 3 inches farther. How can you show how far Harvey goes on a number line?
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 9.1

Look Back!
How are Harvey’s jumps on the number line like repeated addition? How are they like skip counting?

Answer:
Harvey’s jumps on the number line are like skip counting.

Explanation:
In the above-given question,
given that,
Harvey the Hop Toad starts at 0 and jumps 7 times in the same direction.
Each time he jumps 3 inches farther.
0 + 3 = 3.
3 + 3 = 6.
6 + 3 = 9.
9 + 3 = 12.
12 + 3 = 15.
15 + 3 = 18.
18 + 3 = 21.
7 x 3 = 21.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-6

Essential Question
How Can You Use a Number Line to Show Multiplication?

Answer:
7 x 3 = 12.

Explanation:
In the above-given question,
given that,
Harvey the Hop Toad starts at 0 and jumps 7 times in the same direction.
Each time he jumps 3 inches farther.
0 + 3 = 3.
3 + 3 = 6.
6 + 3 = 9.
9 + 3 = 12.
12 + 3 = 15.
15 + 3 = 18.
18 + 3 = 21.
7 x 3 = 21.

Visual Learning Bridge
Clara is making gift bags for her 5 friends. She wants to put 3 glitter pens in each gift bag. How many glitter pens does Clara need?
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 9.2
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 9.30

Convince Me!
Reasoning What would skip counting by 6 look like on the number line?

Answer:
6 look like 6 pens on the number line.

Explanation:
In the above-given question,
given that,
Clara is making gift bags for her 5 friends.
She wants to put 3 glitter pens in each gift bag.
0 + 3 = 3 pens.
3 + 3 = 6 pens.
6 + 3 = 9 pens.
9 + 3 = 12 pens.
12 + 3 = 15 pens.
so 6 on the number line looks like 6 pens.

Guided Practice

Do You Understand?

Question 1.
On the previous page, why do you skip count by 3s on the number line?

Answer:
They skip count by 3s on the number line represents 3 pens.

Explanation:
In the above-given question,
given that,
Clara is making gift bags for her 5 friends.
She wants to put 3 glitter pens in each gift bag.
0 + 3 = 3 pens.
the skip count by 3s on the number line represents 3 pens.

Question 2.
On the previous page, why do you make five jumps on the number line?

Answer:
Clara is making gift bags for her 5 friends.

Explanation:
In the above-given question,
given that,
Clara is making gift bags for her 5 friends.
She wants to put 3 glitter pens in each gift bag.
0 + 3 = 3 pens.
3 + 3 = 6 pens.
6 + 3 = 9 pens.
9 + 3 = 12 pens.
12 + 3 = 15 pens.
so Clara wants to make gift bags for her 5 friends.

Question 3.
How would the jumps on the number line look different if there were 4 pens in each gift bag?

Answer:
Yes, the number line looks different if there were 4 pens in each gift bag.

Explanation:
In the above-given question,
given that,
Clara is making gift bags for her 5 friends.
She wants to put 4 glitter pens in each gift bag.
0 + 4 = 4 pens.
4 + 4 = 8 pens.
8 + 4 = 12 pens.
12 + 4 = 16 pens.

Do You Know How?

In 4, complete the arrows on the number line to show the jumps and fill in the blanks.

Question 4.
Jim ran 3 miles a day for 4 days in a row. How many miles did he run?
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 8.5
Number of jumps: ___
I skip counted by ___.
Jim ran ___ miles.
___ × ___ = ___

Answer:
The number of jumps = 12.
I skip counted by 3.
Jim ran 12 miles.
3 x 4 = 12.

Explanation:
In the above-given question,
given that,
Jim ran 3 miles a day for 4 days in a row.
in one day he ran 3 miles.
in 2 days = 6 miles.
3 days = 9 miles.
4 days = 12 miles.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-7

Independent Practice

In 5, show how you found the solution using the number line.

Question 5.
Judy has 6 fruit baskets. She wants to put 2 apples into each basket. How many apples will she need? Draw the remaining jumps on the number line with arrows to show how many apples Judy will need.
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 9.20
Judy will need __ apples.

Answer:
The number of apples Judy will need = 12.

Explanation:
In the above-given question,
given that,
Judy has 6 fruit baskets.
she wants to put 2 apples into each basket.
0 + 2 = 2.
2 + 2 = 4.
4 + 2 = 6.
6 + 2 = 8.
8 + 2 = 10.
10 + 2 = 12.
6 x 2 = 12.
so the number of apples Judy needs = 12.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-8

in 6 and 7, show the multiplication fact with arrows on the number line. Write the product.

Question 6.
7 × 2 = ___
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 9.33

Answer:
7 x 2 = 14.

Explanation:
In the above-given figure,
given that,
there are 15 numbers on the number line.
7 x 2 = 14.
0 + 2 = 2 in 1st jump.
2 + 2 = 4 in 2nd jump.
4 + 2 = 6 in 3rd jump.
6 + 2 = 8 in 4th jump.
8 + 2 = 10 in 5th jump.
10 + 2 = 12 in 6th jump.
12 + 2 = 14 in 7th jump.
7 x 2 = 14.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-9

Question 7.
3 × 3 = ___
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 9.4

Answer:
3 x 3 = 9.

Explanation:
In the above-given figure,
given that,
there are 15 numbers on the number line.
0 + 3 = 3 in 1st jump.
3 + 3 = 6 in 2nd jump.
6 + 3 = 9 in 3rd jump.
so 3 x 3 = 9.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-9

Problem Solving

Question 8.
Nikki wants to use 3 glass beads in each necklace she is making. She wants to make 6 necklaces. How many glass beads will Nikki need? Use skip counting and write a multiplication equation to solve.
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 9.5

Answer:
The number of glass beads will Nikki need = 18.

Explanation:
In the above-given figure,
given that,
Nikki wants to use 3 glass beads in each necklace she is making.
she wants to make 6 necklaces.
0 + 3 = 3.
3 + 3 = 6.
6 + 3 = 9.
9 + 3 = 12.
12 + 3 = 15.
15 + 3 = 18.
3 x 6 = 18.
so the number of glass beads will Nikki need = 18 beads.

Question 9.
enVision® STEM Guinea pigs in the wild usually live in groups of between 5 and 10. The group members can warn each other of danger. If there are 2 groups of 7 guinea pigs, how many guinea pigs are there in all? Use the number line to solve.
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 9.6

Answer:
The number of guinea pigs in all = 14.

Explanation:
In the above-given question,
given that,
Guinea pigs in the wild usually live in groups of between 5 and 10.
The group members can warn each other of danger.
if there are 2 groups of 7 guinea pigs.
0 + 7 = 7.
7 + 7 = 14.
2 x 7 = 14.
so the number of guinea pigs in all = 14.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-10

Question 10.
Make Sense and Persevere Tim drew this number line to show the multiplication fact 4 × 2 = 8.
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 9.7
Which parts of the number line represent the factors? Which part shows the product?

Answer:
The number line represents the factors are 4, 2, 6, and 8.
the number line that represents the products is 8.

Explanation:
In the above-given question,
given that,
Tim draws this number line to show the multiplication fact 4 x 2 = 8.
so 2, 4, 6 are the factors.
4 x 2 = 8.
8 is the product.

Question 11.
Higher Order Thinking Draw a number line to compare skip counting by 3s four times and skip counting by 4s three times. How are they different? How are they alike?

Assessment Practice

Question 12.
Which of the following contexts do the number line and the expression 5 × 2 represent?
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 9.8
A. 5 groups with 5 pens in each
B. 5 groups with 2 pens in each
C. 2 groups with 2 pens in each
D. 2 groups with 5 pens in each

Answer:
Option B is correct.

Explanation:
In the above-given question,
given that,
0 + 2 = 2.
2 + 2 = 4.
4 + 2 = 6.
6 + 2 = 8.
8 + 2 = 10.
2 + 2 + 2 + 2 + 2 = 10.
5 x 2 = 10.
so 5 groups with 2 pens in each.

Question 13.
Which of the following contexts does the number line and the expression 5 × 3 represent?
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 9.88
A. 5 shelves with 5 books on each
B. 3 shelves with 5 books on each
C. 5 shelves with 3 books on each
D. 3 shelves with 3 books on each

Answer:
Option c is correct.

Explanation:
In the above-given question,
given that,
5 x 3 = 15.
5 shelves with 3 books on each.
0 + 3 = 3.
3 + 3 = 6.
6 + 3 = 9.
9 + 3 = 12.
12 + 3 = 15.
3 + 3 + 3 + 3 + 3 = 15.
5 x 3 = 15.

Lesson 1.3 Arrays and Properties

Activity

Solve & Share

Mark has 12 sports cards. He arranges the cards with an equal number in each row. Find ways Mark can arrange his cards.

Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 10.1

Look Back! What do you notice about the number of rows of cards, the number of cards in each row, and the total number of cards? Explain.

Answer:
2 x 6 = 12.
4 x 3 = 12.
6 x 2 = 12.
3 x 4 = 12.
1 x 12 = 12.
12 x 1 = 12.

Explanation:
In the above-given question,
given that,
Mark has 12 spot cards.
2 x 6 = 12.
4 x 3 = 12.
6 x 2 = 12.
3 x 4 = 12.
1 x 12 = 12.
12 x 1 = 12.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-11

Visual Learning Bridge

Essential Question
How Does an Array Show Multiplication?

A.
Dana keeps her swimming medal collection in a display on the wall.
The display has 4 rows. Each row has 5 medals. How many medals are in Dana’s collection?
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 10.2
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 10.3

B.
The counters show 4 rows and 5 columns.
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 10.4

C.
Multiplication can also be used to find the total in an array.
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 10.5
There are 20 medals in Dana’s collection.

Convince Me!
Construct Arguments Jason also has a swimming medal collection. His display has 5 rows with 5 medals in each row. Draw an array for Jason’s medals. Use skip counting to find the total number of medals. Then write a multiplication equation for your array. Who has more medals, Jason or Dana?

Answer:
Jason has more medals.

Explanation:
In the above-given question,
given that,
Jason also has a swimming medal collection.
His display has 5 rows with 5 medals in each row.
5 x 5 = 25.
Dana has only 20 medals.
Jason has more medals.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-12

Another Example!
Dana rearranged her swimming medal collection. The arrays have the same number of medals.
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 11.2
Envision Math Common Core Grade 3 Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 11.3

Guided Practice

Do You Understand?

Question 1.
Mia puts muffins in 4 rows with 7 muffins in each row. Draw an array to find the total number of muffins.

Answer:
The total number of muffins = 28 muffins.

Explanation:
In the above-given question,
given that,
Mia puts muffins in 4 rows with 7 muffins in each row.
There are 4 rows.
In each row, there are 7 muffins.
4 x 7 = 28.
7 x 4 = 28.
so the total number of muffins = 28 muffins.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-13

Question 2.
Complete the following statement.
4 × 7 = 28, so 7 × 4 = ___.

Answer:
7 x 4 = 28.

Explanation:
In the above-given question,
given that,
4 x 7 = 28.
7 x 4 = 28.

Do You Know How?

In 3, write and solve a multiplication equation for the array.

Question 3.
Envision Math Common Core 3rd Grade Answers Topic 1 Understand Multiplication and Division of Whole Numbers 11.4

Answer:
4 x 6 = 24.

Explanation:
In the above-given question,
given that,
The multiplication for the given array.
there are 4 rows.
in each row, there are 6.
4 x 6 = 24.

Independent Practice

In 4 and 5, fill in the blanks to show skip counting and multiplication for each array.

Question 4.
Envision Math Common Core 3rd Grade Answers Topic 1 Understand Multiplication and Division of Whole Numbers 12.1

Answer:
2, 4, 6, 8.
4 x 2 = 8.
4, 8.
2 x 4 = 8.

Explanation:
In the above-given question,
given that,
2 + 2 = 4.
4 + 2 = 6.
6 + 2 = 8.
2 x 4 = 8.
4 x 2 = 8.

Question 5.
Envision Math Common Core 3rd Grade Answers Topic 1 Understand Multiplication and Division of Whole Numbers 12.2

Answer:
3, 6, 9, and 12.
4 x 3 = 12.
4, 8, and 12.
3 x 4 = 12.

Explanation:
In the above-given question,
given that,
3 + 3 = 6.
3 + 6 = 9.
9 + 3 = 12.
4 x 3 = 12.
3 x 4 = 12.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-14

Problem Solving

Question 6.
Liza draws these two arrays. How are the arrays alike? How are they different?
Envision Math Common Core 3rd Grade Answers Topic 1 Understand Multiplication and Division of Whole Numbers 12.3

Answer:
5 x 3 = 15.
3 x 5 = 15.

Explanation:
In the above-given question,
given that,
they are the same when the total number of arrays is 15.
they are different when the number of rows and number of columns is not equal.
for example 5 x 3 = 15.
2 x 3 = 6.

Question 7.
Use Structure Chen arranged 16 berries in the array shown below. Use counters to help complete the table to show other arrays Chen can make with the same number of berries.
Envision Math Common Core 3rd Grade Answers Topic 1 Understand Multiplication and Division of Whole Numbers 12.4

Answer:
8 x 2 = 16.
2 x 8 = 16.
1 x 16 = 16.
16 x 1 = 16.

Explanation:
In the above-given question,
given that,
the number of rows of berries = 4.
the number of columns of berries = 4.
the total number of berries = 16.
2 x 8 = 16.
8 x 2 = 16.
1 x 16 = 16.
16 x 1 = 16.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-15

Question 8.
Higher Order Thinking Ramón says he can use the Commutative Property of Multiplication to show the product of 4 × 6 is the same as the product of 3 × 8. Is he correct? Why or why not?

Answer:
No, he was not correct.

Explanation:
In the above-given question,
given that,
Ramon says he can use the commutative property of multiplication to show the product of 4 x 6 is not as same as 3 x 8.
In commutative property we can write 4 x 6 = 24.
6 x 4 = 24.
so Ramon was not correct.

Question 9.
Delbert put 5 nickels in each of his 3 empty piggy banks. How many nickels did Delbert put in the banks? Write a multiplication equation to show how you solved the problem.
Envision Math Common Core 3rd Grade Answers Topic 1 Understand Multiplication and Division of Whole Numbers 12.5

Answer:
The number of nickels did Delbert put in the banks = 15.

Explanation:
In the above-given question,
given that,
Delbert put 5 nickels in each of his 3 empty piggy banks.
multiplication equation is 3 x 5 = 15.
so the number of nickels did Delbert put in the banks = 15.

Assessment Practice

Question 10.
An equation is shown.
8 × 5 = 5 × Envision Math Common Core 3rd Grade Answers Topic 1 Understand Multiplication and Division of Whole Numbers 13
Use the Commutative Property of Multiplication to find the missing factor.
A. 5
B. 8
C. 40
D. 85

Answer:
Option B is correct.

Explanation:
In the above-given question,
given that,
8 x 5 = 40.
5 x 8 = 40.
so option B is correct.

Question 11.
Using the Commutative Property of Multiplication, which of the following expressions is equivalent to 5 × 4?
A. 5 + 5
B. 4 × 5
C. 5 + 4
D. 5 – 4

Answer:
5 x 4 = 4 x 5.

Explanation:
In the above-given question,
given that,
commutative property of multiplication of expression 5 x 4 = 20.
4 x 5 = 20.
so 5 x 4 = 4 x 5.

Lesson 1.4 Division: How Many in Each Group?

Activity

Solve & Share

Six friends picked 48 grapefruits. They want to share them equally. How many grapefruits should each friend get?
Envision Math Common Core 3rd Grade Answers Topic 1 Understand Multiplication and Division of Whole Numbers 13.6
Envision Math Common Core 3rd Grade Answers Topic 1 Understand Multiplication and Division of Whole Numbers 13.66

Look Back!
How can you use counters to help solve this problem? Explain.

Answer:
6 x 8 = 48.

Explanation:
In the above-given question,
given that,
Six friends picked 48 grapefruits.
They want to share them equally.
6 x 8 = 48.

Visual Learning Bridge

Essential Question
How Many are in Each Group?

A.
Three friends have 12 toys to share equally. How many toys will each friend get?
Think of arranging 12 toys into 3 equal groups.
Envision Math Common Core 3rd Grade Answers Topic 1 Understand Multiplication and Division of Whole Numbers 13.7

Envision Math Common Core 3rd Grade Answers Topic 1 Understand Multiplication and Division of Whole Numbers 13.8
Division is an operation that is used to find how many equal groups there are or how many are in
each group.

B. What You Think
Put one toy at a time in each group.
Envision Math Common Core 3rd Grade Answers Topic 1 Understand Multiplication and Division of Whole Numbers 13.9
When all the toys are grouped, there will be 4 in each group.

C. What You Write You can write a division equation to find the number in each group.
Envision Math Common Core 3rd Grade Answers Topic 1 Understand Multiplication and Division of Whole Numbers 14.1
Each friend will get 4 toys.

Convince Me!
Be Precise What would happen if 3 friends wanted to share 13 toys equally?

Answer:
13 / 3 = 4.3

Explanation:
In the above-given question,
given that,
if 3 friends wanted to share 13 toys each.
13 / 3 = 4.3.
nearly 4 toys will share 3 friends.

Guided Practice

Do You Understand?

Question 1.
Eighteen eggs are divided into 3 rows. How many eggs are in each row? Use the bar diagram to solve.

Answer:
The number of eggs in each row = 6.

Explanation:
In the above-given question,
given that,
18 eggs are divided into 3 rows.
18 / 3 = 6.
so the number of eggs in each row = 6.

Question 2.
Can 12 grapes be shared equally among 5 children with no grapes remaining? . Explain.

Answer:
No.

Explanation:
In the above-given question,
given that,
12 grapes are shared equally among 5 children.
12 / 5 = 2.4.
2 grapes are remaining.
so 12 grapes cannot be shared equally among 5 children.

Do You Know How?

In 3 and 4, draw a picture to solve.

Question 3.
Fifteen bananas are shared equally by 3 monkeys. How many bananas does each monkey get?

Answer:
The number of bananas does each monkey gets =

Explanation:
In the above-given question,
given that,
Fifteen bananas are shared equally by 3 monkeys.
15 / 3 = 5.
so the number of bananas does each monkey gets = 5.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-16

Question 4.
Sixteen plants are divided equally into 4 pots. How many plants are in each pot?

Answer:
The number of plants in each pot = 4.

Explanation:
In the above-given question,
given that,
sixteen plants are divided equally into 4 pots.
16 / 4 = 4.
so the number of plants in each pot = 4.

Independent Practice

In 5 and 6, draw a picture to solve.

Question 5.
Eighteen marbles are divided equally into 6 sacks. How many marbles are in each sack?

Answer:
The number of marbles is in each sack = 3.

Explanation:
In the above-given question,
given that,
Eighteen marbles are divided equally into 6 sacks.
18 / 6 = 3.
so the number of marbles in each sack = 3.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-17

Question 6.
Sixteen crayons are shared equally by 2 people. How many crayons does each person have?

Answer:
The number of crayons does each person has = 8.

Explanation:
In the above-given question,
given that,
sixteen crayons are shared equally by 2 people.
16 / 2 = 8.
so the number of crayons does each person has = 8.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-18

In 7-10, complete each equation.

Question 7.
Envision Math Common Core 3rd Grade Answers Topic 1 Understand Multiplication and Division of Whole Numbers 15.1

Answer:
12 / 2 = 6.

Explanation:
In the above-given question,
given that,
12 / 2 = 6.
6 x 2 = 12.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-19

Question 8.
Envision Math Common Core 3rd Grade Answers Topic 1 Understand Multiplication and Division of Whole Numbers 15.2

Answer:
16 / 8 = 2.

Explanation:
In the above-given question,
given that,
16 / 8 = 2.
2 x 8 = 16.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-20

Question 9.
9 ÷ 3 = ___

Answer:
9 / 3 = 3.

Explanation:
In the above-given question,
given that,
9 / 3 = 3.
3 x 3 = 9.

Question 10.
14 ÷ 7 = __

Answer:
14 / 7 = 2.

Explanation:
In the above-given question,
given that,
14 / 7 = 2.
7 x 2 = 14.

Problem Solving

Question 11.
Jim is putting 18 pens into equal groups. He says if he puts them into 2 equal groups he will have more pens in each group than if he puts them into 3 equal groups. Is Jim correct? Explain.

Answer:
Yes, Jim was correct.

Explanation:
In the above-given question,
given that,
Jim is putting 18 pens into equal groups.
He says if he puts them into 2 equal groups he will have more pens.
if he puts them into 3 equal groups.
6 + 6 + 6 = 18.
3 x 6 = 18.
so Jim was correct.

Question 12.
Make Sense and Persevere Ms. Terry’s class is hosting a fundraising challenge. The students in her class are divided into 4 teams. Each team has an equal number of students. Do you have enough information to find how many students are on each team? Explain.

Answer:
The number of students is on each team = 16.

Explanation:
In the above-given question,
given that,
Ms. Terry’s class is hosting a fundraising challenge.
The students in her class are divided into 4 teams.
Each team has an equal number of students.
4 + 4 + 4 + 4 = 16.
4 x 4 = 16.
16 / 4 = 4.
so the number of students are on each team = 16.

Question 13.
Erika draws a hexagon. Maria draws a pentagon. Who draws the shape with more sides? How many more sides does that shape have?

Answer:
Erika draws more sides.

Explanation:
In the above-given question,
given that,
Erika draws a hexagon.
Maria draws a pentagon.
hexagon has one more side than the pentagon.
Pentagon has 5 sides.
hexagon has 6 sides.

Question 14.
The flag bearers in a parade march in 9 rows with 5 flags in each row. Write an equation to show how many flags there are.

Answer:
The number of flags is there = 45.

Explanation:
In the above-given question,
given that,
the flag bearers in a parade march in 9 rows with 5 flags in each row.
9 x 5 = 45.
45 /  5 = 9.
45 / 9 = 5.
so the number of flags are there = 45.

Question 15.
Number Sense Jenn and some friends share 40 jellybeans equally. Is the number that each friend gets greater than 40 or less than 40? Explain.

Answer:
Each friend gets less than 40.

Explanation:
In the above-given question,
given that,
Jenn and some friends share 40 jellybeans equally.
8 x 5 = 40.
so 8 friends share 5 jellybeans each.
so each friend gets less than 40.

Question 16.
Higher Order Thinking Joy has 12 shells. She gives 2 shells to her mom. Then she and her sister share the rest of the shells equally. How many shells does Joy get? How many shells does her sister get? How do you know?

Answer:
The number of shells Joy gets = 5.
the number of shells her sister gets = 5.

Explanation:
In the above-given question,
given that,
Joy has 12 shells.
She gives 2 shells to her mom.
Then she and her sister share the rest of the shells equally.
12 – 2 = 10.
5 + 5 = 10.
so the number of shells Joy get = 5.
the number of shells her sister get = 5.

Assessment Practice

Question 17.
Which of the following contexts does the expression 14 ÷ 2 represent? @ 14 pens arranged in
A. 14 pens arranged in 14 equal groups
B. 2 pens arranged in 14 equal groups
C. 14 pens arranged in 2 equal groups
D. 2 pens arranged in 2 equal groups

Answer:
Option B is correct.

Explanation:
In the above-given question,
given that,
the expression 14/2 represents
2 pens arranged in 14 equal groups.
so option B is correct.

Question 18.
Which of the following contexts does the expression 12 ÷ 3 represent?
A. 12 books arranged equally on 3 shelves
B. 12 books arranged equally on 12 shelves
C. 3 books arranged equally on 12 shelves
D. 3 books arranged equally on 3 shelves

Answer:
Option C is correct.

Explanation:
In the above-given question,
given that,
the expression 12 / 3 represents,
3 books arranged on 12 shelves.
so option C is correct.

Lesson 1.5 Division: How Many Equal Groups?

Activity

Solve & Share

Li made 12 tacos. He wants to give some of his friends 2 tacos each. If Li does not get any of the tacos, how many of his friends will get tacos?

Envision Math Common Core 3rd Grade Answers Topic 1 Understand Multiplication and Division of Whole Numbers 200
You can use reasoning. How can what you know about sharing help you solve the problem?

Answer:
The number of friends gets 2 tacos each = 6.

Explanation:
In the above-given question,
given that,
I made 12 tacos. He wants to give some of his friends 2 tacos each.
12 / 2 = 6.
so the number of friends gets 2 tacos each = 6.

Look Back!
How can counters or other objects help you show your work?

Visual Learning Bridge

Essential Question
How Can You Divide Using Repeated Subtraction?

A.
June has 10 strawberries to serve to her guests. If each guest eats 2 strawberries, how many guests can June serve?

Envision Math Common Core 3rd Grade Answers Topic 1 Understand Multiplication and Division of Whole Numbers 20.2

B. You can use repeated subtraction to find how many groups of 2 are in 10.
Envision Math Common Core 3rd Grade Answers Topic 1 Understand Multiplication and Division of Whole Numbers 203

C.
Envision Math Common Core 3rd Grade Answers Topic 1 Understand Multiplication and Division of Whole Numbers 20.33
You can write a division equation to find the number of groups.
Write: 10 ÷ 2 = ?
Read: Ten divided by 2 equals what number?
Solve: 10 ÷ 2 = 5
June can serve 5 guests.

Convince Me!
Model with Math In the example above, what if each guest ate 5 strawberries? Use math you know to represent the problem and find how many guests June could serve.

Answer:
June could serve 2 guests.

Explanation:
In the above-given question,
given that,
if each guest ate 5 strawberries,
10 / 5 = 2.
10 – 5 = 5.
5 – 5 = 0.
so June could serve 2 guests.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-21

Guided Practice

Do You Understand?

Question 1.
There are 3 boxes with 2 toys in each box. The total number of toys can be expressed as 3 × 2 = 6. What is meant by 6 ÷ 3 = 2? What is meant by 6 ÷ 2 = 3?

Answer:
6 / 3 means there is the total number of toys by the total number of boxes.
6 / 2 means there is the total number of boxes by the total number of toys.

Explanation:
In the above-given question,
given that,
There are 3 boxes with 2 toys in each box.
the total number of toys can be expressed as 3 x 2 = 6.
so the total number of toys by the total number of boxes is 6 / 3.
so the total number of boxes by the total number of toys = 6 / 2.

Do You Know How?

In 2 and 3, use counters or draw a picture to solve.

Question 2.
The lost and found box has 16 gloves. There are 2 gloves in each pair. How many pairs of gloves are there?

Answer:
The number of pairs of gloves is there = 8 gloves.

Explanation:
In the above-given question,
given that,
The lost and found box has 16 gloves.
There are 2 gloves in each pair.
16 / 2 = 8.
16 – 8 = 8.
8 – 8 = 0.
so the number of pairs of gloves are there = 8.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-22

Question 3.
Ruth gives her dogs 15 treats. Each dog gets 3 treats. How many dogs does Ruth have?

Answer:
The number of dogs does Ruth has = 5 dogs.

Explanation:
In the above-given question,
given that,
Ruth gives her dogs 15 treats.
Each dog gets 3 treats.
15 / 3 = 5.
15 – 5 = 10.
10 – 5 = 5.
5 – 5 = 0.
so the number of dogs does Ruth have = 5 dogs.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-23

Independent Practice

Leveled Practice In 4 and 5, complete the equations.

Question 4.
Rosa picks 14 apples. She places 7 apples in each bag. How many bags does Rosa have?
14 – 7 = ___
__ – 7 = __
___ ÷ 7 = __
Rosa has ___ bags.

Answer:
The number of bags Rosa has = 2 bags.

Explanation:
In the above-given question,
given that,
Rosa picks 14 apples.
She places 7 apples in each bag.
14 – 7 = 7.
7 – 7 = 0.
14 / 7 = 2.
so the number of bags Rosa have = 2 bags.

Question 5.
The wagons on the farm have 4 wheels each. There are 12 wheels. How many wagons are on the farm?
12 – 4 = ___
__ – 4 = ___
__ – ___ = ___
There are ___ wagons.

Answer:
The number of wagons is on the farm = 3 wagons.

Explanation:
In the above-given question,
given that,
The wagons on the farm have 4 wheels each.
There are 12 wheels.
12 / 4 = 3.
12 – 4 = 8.
8 – 4 = 4.
4 – 4 = 0.
so the number of wagons are on the farm = 3 wagons.

In 6 and 7, use counters or draw a picture to solve.

Question 6.
Maria bought 30 markers that came in packages of 5 markers each. How many packages did Maria buy?

Answer:
The number of packages did Maria buy = 6.

Explanation:
In the above-given question,
given that,
Maria bought 30 markers that came in packages of 5 markers each.
30 / 5 = 6.
30 – 5 = 25.
25 – 5 = 20.
20 – 5 = 15.
15 – 5 = 10.
10 – 5 = 5.
5 – 5 = 0.
so the number of packages did Maria buy = 6.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-24

Question 7.
Marcus has 18 pencils. He places 2 pencils on each desk. How many desks are there?

Answer:
The number of desks is there = 9.

Explanation:
In the above-given question,
given that,
Marcus has 18 pencils.
He places 2 pencils on each desk.
18 / 2 = 9.
18 – 9 = 9.
9 – 9 = 0.
so the number of desks are there = 9.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-25

Problem Solving

Question 8.
Generalize The chart shows the number of pennies each of three friends has in her pocket. Each friend divides her money into groups of 3 coins. Write division equations to show how many equal groups each friend can make. Explain what repeats in the equations.
Envision Math Common Core 3rd Grade Answers Topic 1 Understand Multiplication and Division of Whole Numbers 30.1

Answer:
18 / 3 = 6.
12 / 3 = 4.
15 / 3 = 5.

Explanation:
In the above-given question,
given that,
The chart shows the number of pennies each of the three friends has in her pocket.
Claudia has 18 cents in her pocket.
18 / 3 = 6.
Zoe has 12 cents in her pocket.
12 / 3 = 4.
Jenna has 15 cents in her pocket.
15 / 3 = 5.

Question 9.
If Zoe has 6 pennies in each row, how many rows does she make?

Answer:
The number of rows does she make = 2.

Explanation:
In the above-given question,
given that,
If Zoe has 6 pennies in each row.
12 / 6 = 2.
12 – 6 = 6.
6 – 6 = 0.
so the number of rows does she make = 2.

Question 10.
Bella has $52. She spends $21, and then finds $12. How much money does she have now? Use equations to represent the problem.

Answer:
The money does she have now = $43.

Explanation:
In the above-given question,
given that,
Bella has $52.
she spends $21 and then finds $12.
$52 – $21 = $31.
$31 + $12 = $43.
so the money does she have now = $43.

Question 11.
Higher Order Thinking An ice cream store plans to make 8 new flavors each year. How many years will it take for the store to make 80 flavors? Write and solve an equation.

Answer:
The number of years will it take for the store to make 80 flavors = 10 years.

Explanation:
In the above-given question,
given that,
An ice cream store plans to make 8 new flavors each year.
80 / 8 = 10.
80 – 8 = 72.
72 – 8 = 64.
64 – 8 = 56.
56 – 8 = 48.
48 – 8 = 40.
40 – 8 = 32.
32 – 8 = 24.
24 – 8 = 16.
16 – 8 = 8.
8 – 8 = 0.
so the number of years will it take for the store to make 80 flavors = 10 years.

Assessment Practice

Question 12.
Eric writes 20 ÷ 5. Which problem could Eric’s expression represent?
A. There are 20 apples. Each guest gets 10 apples. How many guests are there?
B. There are 20 pencils. Each student gets 2 pencils. How many students are there?
C. There are 5 pens. Each student gets 1 pen. How many students are there?
D. There are $20. Each child gets $5. How many children are there?

Answer:
Option D is correct.

Explanation:
In the above-given question,
given that,
there are $20.
each child gets $5.
20 / 5 = 4.
so option D is correct.

Question 13.
Jacqui writes 24 ÷ 8. Which problem could Jacqui’s expression represent?
A. There are 24 bows. Each child gets 8 bows. How many children are there?
B. There are 24 chicks. Each box holds 2 chicks. How many boxes are there?
C. There are 24 horses. Each arena has 12 horses. How many arenas are there?
D. There are 24 coins. Each pile has 24 coins. How many piles are there?

Answer:
Option A is correct.

Explanation:
In the above-given question,
given that,
Jacqui writes 24 /8 = 4.
there are 24 bows.
Each child gets 8 bows.
24 – 8 = 16.
16 – 8 = 8.
8 – 8 = 0.
so option A is correct.

Lesson 1.6 Use Appropriate Tools

Problem Solving

Activity

Solve & Share

Carolyn earned $8 a week for 2 weeks. She wants to buy some books that cost $4 each. How many books can she buy?
Choose a tool to represent and solve the problem. Explain why you chose that tool.

Answer:
The number of books she can buy = 4 books.

Explanation:
In the above-given question,
given that,
Carolyn earned $8 a week for 2 weeks.
She wants to buy some books that cost $4 each.
$ 8 + $ 8 = $ 16.
$ 16 / $ 4 = $ 4.
so the number of books she can buy = $ 4.

Thinking Habits
Be a good thinker!
These questions can help you.
∙ Which tools can I use?
∙ Why should I use this tool to help me solve the problem?
∙ Is there a different tool I could use?
∙ Am I using the tool appropriately?
Envision Math Common Core 3rd Grade Answers Topic 1 Understand Multiplication and Division of Whole Numbers 30.99

Look Back!
Use Appropriate Tools Explain how you used the tool you chose.

Visual Learning Bridge

Essential Question
How Can You Use Appropriate Tools to Represent and Solve Problems?

A.
A hardware store has boxes of 18 light bulbs. 3 light bulbs cost $4. How much does it cost to buy a whole box of light bulbs? Choose a tool to represent and solve the problem.

Sometimes you can use more than one tool to help you solve problems.
Envision Math Common Core 3rd Grade Answers Topic 1 Understand Multiplication and Division of Whole Numbers 50.1

What do I need to do?
I need to choose an appropriate tool to help me find how much it costs to buy a box of 18 light bulbs.

B. Which tools can I use to help me solve this problem?

I can

  • decide which tools are appropriate.
  • use cubes and counters to solve this problem.
  • use the tools correctly.

C.
Here’s my thinking…
Envision Math Common Core 3rd Grade Answers Topic 1 Understand Multiplication and Division of Whole Numbers 50.2
I will use two tools. Both counters and ones cubes are easy to count and move around.
Each cube is 1 light bulb. I will separate 18 cubes into groups of 3.
Each counter is $1. I will put 4 counters with each group of 3 light bulbs.
There are 24 counters. A box of light bulbs costs $24.
Envision Math Common Core 3rd Grade Answers Topic 1 Understand Multiplication and Division of Whole Numbers 50.3

Convince Me!
Use Appropriate Tools What other tools could you use to help solve this problem?

Guided Practice

Use Appropriate Tools
Three friends each have 8 books. They put their books into 4 equal piles. How many books are in each pile?
Envision Math Common Core Grade 3 Answers Topic 1 Understand Multiplication and Division of Whole Numbers 50.4
You can also use appropriate digital tools. Technology can help you solve a problem.

Answer:
The number of books in each pile = 6.

Explanation:
In the above-given question,
given that,
three friends each have 8 books.
they put their books into 4 equal piles.
each cube is 1 book.
I will separate 4 books into groups of 8.
8 / 4 = 2.
2 x 3 = 6.
so the number of books in each pile = 6.

Question 1.
Choose a tool to represent the problem. Explain why you chose that tool.

Answer:
I use cubes to represent the problem.

Explanation:
In the above-given question,
given that,
three friends each have 8 books.
they put their books into 4 equal piles.
each cube is 1 book.
I will separate 4 books into groups of 8.
8 / 4 = 2.
2 x 3 = 6.
so the number of books in each pile = 6.

Question 2.
Solve the problem. Explain how you used the tool you chose.

Answer:
The number of books in each pile = 6.

Explanation:
In the above-given question,
given that,
three friends each have 8 books.
they put their books into 4 equal piles.
each cube is 1 book.
I will separate 4 books into groups of 8.
8 / 4 = 2.
2 x 3 = 6.
so the number of books in each pile = 6.

Independent Practice
Use Appropriate Tools

Fifteen students are working in equal groups to make posters. There are 5 students in each group. For each group of students, there needs to be 2 adults helping. How many adults are needed?

Question 3.
Choose a tool to represent the problem. Explain why you chose that tool.

Answer:
I used cubes to solve the problem.

Explanation:
In the above-given question,
given that,
for 1 cube I am representing 5 students.
15 / 5 = 3.
3 x 2 = 6.
cubes are easy to solve the problem.
so I used cubes to solve.

Question 4.
Solve the problem. Explain how you used the tool you chose.

Answer:
The number of adults is needed = 6.

Explanation:
In the above-given question,
given that,
Fifteen students are working in equal groups to make posters. There are 5 students in each group. For each group of students, there needs to be 2 adults helping.
15 / 5 = 3.
3 x 2 = 6.
so the number of adults are needed = 6.

Question 5.
The posters need to be 20 inches long. What tool could the students use to check that the posters are the correct size? Explain how they could use this tool.

Answer:
Problem Solving

Performance Task

Bottle Cap Display
The soda bottle caps at the right are shared equally between Kerry and Nita. There are 4 orange bottle caps. Kerry wants to arrange her bottle caps into an array.
Envision Math Common Core 3rd Grade Answers Topic 1 Understand Multiplication and Division of Whole Numbers 50.5

Answer:
The bottle caps into an array is 4 x 3 = 12.

Explanation:
In the above-given question,
given that,
The soda bottle caps at the right are shared equally between Kerry and Nita.
There are 4 orange bottle caps.
total there are 16 bottle caps.
16 – 4 = 12.
12 / 4 = 3.
so the bottle caps into an array is 4 x 3 = 12.

Question 6.
Make Sense and Persevere What do you need to find out before you make an array? Show a way to find this. You can use a tool to help.

Answer:
16 – 4 = 12.

Explanation:
In the above-given question,
given that,
The soda bottle caps at the right are shared equally between Kerry and Nita.
There are 4 orange bottle caps.
total there are 16 bottle caps.
16 – 4 = 12.
12 / 4 = 3.
so the bottle caps into an array is 4 x 3 = 12.

Question 7.
Use Appropriate Tools Choose a tool to represent Kerry’s array of soda bottle caps. Explain why you chose that tool.

Answer:
I choose a tool that is the cubes model.

Explanation:
In the above-given question,
given that,
one cube is equal to the 1 bottle cap.
The soda bottle caps at the right are shared equally between Kerry and Nita.
There are 4 orange bottle caps.
total there are 16 bottle caps.
16 – 4 = 12.
12 / 4 = 3.
so the bottle caps into an array is 4 x 3 = 12.

Question 8.
Model with Math Draw a picture to show how Kerry’s array might look. Then write a multiplication equation for the array.
Answer:

Envision Math Common Core Grade 3 Answers Topic 1 Understand Multiplication and Division of Whole Numbers 50.6
Think about what you need to do in the problem. Then use appropriate tools that can help you solve it.

Question 9.
Use Structure Write a different multiplication equation with the same two factors you used in Exercise 8. Has the product changed? Explain.
Answer:

Question 10.
Critique Reasoning Kerry says she can use a tens rod to represent the array. Do you agree? Explain.
Answer:

Topic 1 Fluency Review Activity

Find a Match

Work with a partner. Point to a clue. Read the clue.
Look below the clues to find a match. Write the clue letter in the box next to the match.
Find a match for every clue.

Envision Math Common Core Grade 3 Answers Topic 1 Understand Multiplication and Division of Whole Numbers 50.7

Envision Math Common Core Grade 3 Answers Topic 1 Understand Multiplication and Division of Whole Numbers 60.3 3 + 0

Envision Math Common Core Grade 3 Answers Topic 1 Understand Multiplication and Division of Whole Numbers 60.3 15 – 8

Envision Math Common Core Grade 3 Answers Topic 1 Understand Multiplication and Division of Whole Numbers 60.3 10 + 7

Envision Math Common Core Grade 3 Answers Topic 1 Understand Multiplication and Division of Whole Numbers 60.3 5 + 5

Envision Math Common Core Grade 3 Answers Topic 1 Understand Multiplication and Division of Whole Numbers 60.3 10 + 6

Envision Math Common Core Grade 3 Answers Topic 1 Understand Multiplication and Division of Whole Numbers 60.3 9 + 4

Envision Math Common Core Grade 3 Answers Topic 1 Understand Multiplication and Division of Whole Numbers 60.3 13 – 9

Envision Math Common Core Grade 3 Answers Topic 1 Understand Multiplication and Division of Whole Numbers 60.3 8 + 7

Envision Math Common Core Grade 3 Answers Topic 1 Understand Multiplication and Division of Whole Numbers 60.3 9 – 9

Envision Math Common Core Grade 3 Answers Topic 1 Understand Multiplication and Division of Whole Numbers 60.3 4 + 4

Envision Math Common Core Grade 3 Answers Topic 1 Understand Multiplication and Division of Whole Numbers 60.3 12 + 8

Envision Math Common Core Grade 3 Answers Topic 1 Understand Multiplication and Division of Whole Numbers 60.3 10 + 9

Answer:
3 + 0 = 3.
15 – 8 = 7.
10 + 7 = 17.
5 + 5 = 10.
10 + 6 = 16.
9 + 4 = 13.
13 – 9 = 4.
8 + 7 = 15.
9 – 9 = 0.
4 + 4 = 8.
12 + 8 = 20.
10 + 9 = 19.

Explanation:
In the above-given question,
given that,
20 = A, 7 = B, 16 = C, 4 = D, 10 = E, 15 = F, 3 = G, 17 = H, 0 = I, 19 = J, 8 = K, 13 = L.
3 + 0 = 3.
15 – 8 = 7.
10 + 7 = 17.
5 + 5 = 10.
10 + 6 = 16.
9 + 4 = 13.
13 – 9 = 4.
8 + 7 = 15.
9 – 9 = 0.
4 + 4 = 8.
12 + 8 = 20.
10 + 9 = 19.

Topic 1 Vocabulary Review

Glossary

Word List

• array
• column
• Commutative Property of Multiplication
• division
• equal groups
• equation
• factors
• multiplication
• number line
• product
• row
• unknown

Understand Vocabulary

Choose the best term from the Word List. Write it on the blank.

Question 1.
___ is an operation you can use to join

Answer:
The addition and multiplication is an operation used to join.

Explanation:
In the above-given question,
given that,
addition and multiplication is an operation we can use to join.
for example:
2 + 3 = 5.
3 x 2 = 6.

Question 2.
You solve an equation by finding the value that is ___

Answer:
We can solve an equation by finding the value that is unknown.

Explanation:
In the above-given question,
given that,
we can solve an equation by finding the value that is unknown.
for example:
there are 12 mangoes.
they have to share 3 friends equally.
so each friend will get how many mangoes?
12 / 3 = 4.

Question 3.
You can use a(n) ___ to display objects in rows and columns.

Answer:
We can use an array to display objects in rows and columns.

Explanation:
In the above-given question,
given that,
we can use an array to display objects in rows and columns.

Question 4.
A line marked in equal units and numbered in order is called : a(n) ___

Answer:
A line marked in equal units and numbered in order is called a number line.

Explanation:
In the above-given question,
given that,
A line marked in equal units and numbered in order is called a number line.
In number, line numbers are jumping in order.
for example:
In a number line, there are 8 numbers and jumping by 2.
0 + 2  = 2.
2 + 2 = 4.
4 + 2 = 6.
6 + 2 = 8.

For each of these terms, give an example and a non-example.

Envision Math Common Core Grade 3 Answers Topic 1 Understand Multiplication and Division of Whole Numbers 60.8

Answer:
5. 20 / 5 = 4, and 25 / 5 = 4.
6. 5 x 4 = 20, and 5 x 5 = 20.
7. 4 x 3 = 12, and 3 x 4 = 15.

Explanation:
In the above-given question,
given that,
give an example and non-example of division, equation, and the commutative property.
20 / 5 = 4 and 25 / 5 = 4.
5 x 4 = 20 and 5 x 5 = 25.
4 x 3 = 12 and 3 x 4 = 12.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-26

Use Vocabulary in Writing

Question 8.
Explain how you can multiply 3 × 4. Use at least 2 terms from the Word List in your explanation.

Answer:
3 x 4 = 12.
4 x 3 = 12.

Explanation:
In the above-given question,
given that,
we can use the two terms multiplication and factors.
if we multiply we get 3 x 4 = 12.
3 and 4 are the factors.
12 is the product.

Topic 1 Reteaching

Set A
pages 5-8
How many is 3 groups of 4?
Envision Math Common Core Grade 3 Answers Topic 1 Understand Multiplication and Division of Whole Numbers 60.9

Remember that you can use addition or multiplication to join equal groups.
Complete each equation. Use counters or draw a picture to help.

Question 1.
2 + 2 + 2 = 3 × ___

Answer:
3 x 2 = 6.

Explanation:
In the above-given question,
given that,
we can use addition or multiplication to join equal groups.
3 groups of 2.
2 + 2 + 2 = 6.
3 x 2 = 6.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-27

Question 2.
___+ ___ + ___ = 3 × 6

Answer:
3 x 6 = 18.

Explanation:
In the above-given question,
given that,
we can use addition or multiplication to join equal groups.
3 groups of 6.
6 + 6 + 6 = 18.
3 x 6 = 18.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-28

Question 3.
8 + __ + ___= ___ × 8

Answer:
3 x 8 = 24.

Explanation:
In the above-given question,
given that,
we can use addition or multiplication to join equal groups.
3 groups of 8.
8 + 8 + 8 = 24.
3 x 8 = 24.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-29

Set B
pages 9-12
Skip count by 4s three times.
Envision Math Common Core Grade 3 Answers Topic 1 Understand Multiplication and Division of Whole Numbers 70.1

Remember that you can show skip counting on a number line.
Use the number line to complete each multiplication equation.

Question 1.
2 × 3 = ___
Envision Math Common Core Grade 3 Answers Topic 1 Understand Multiplication and Division of Whole Numbers 70.2

Answer:
2 x 3 = 6.

Explanation:
In the above-given question,
given that,
the number of jumps = 2.
number in each jump = 3.
2 x 3 = 6.
2 + 2 + 2 = 6.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-30

Question 2.
4 × 3 = ___
Envision Math Common Core Grade 3 Answers Topic 1 Understand Multiplication and Division of Whole Numbers 70.3

Answer:
4 x 3 = 12.

Explanation:
In the above-given question,
given that,
the number of jumps = 4.
number in each jump = 3.
4 x 3 = 12.
4 + 4 + 4 = 12.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-31

Set C
pages 13-16
Find 4 × 6. The array shows 4 rows of 6 counters.
Envision Math Common Core Grade 3 Answers Topic 1 Understand Multiplication and Division of Whole Numbers 70.5
Each row is an equal group. You can use skip counting or multiplication to find the total.

Answer:
4 x 6 = 24.

Explanation:
In the above-given question,
given that,
the number of rows = 4.
number in each column = 6.
4 x 6 = 24.

Remember that an array shows objects in equal rows.
Show how to use skip counting and multiplication for each array.

Question 1.
Envision Math Common Core Grade 3 Answers Topic 1 Understand Multiplication and Division of Whole Numbers 70.6

Answer:
2 x 4 = 8.

Explanation:
In the above-given question,
given that,
the number of rows = 2.
number in each column = 4.
2 x 4 = 8.
2 + 2 + 2 + 2 = 8.

Question 2.
Envision Math Common Core Grade 3 Answers Topic 1 Understand Multiplication and Division of Whole Numbers 70.7

Answer:
3 x 6 = 18.

Explanation:
In the above-given question,
given that,
the number of rows = 3.
number in each column = 6.
3 x 6 = 18.
3 + 3 + 3 + 3 + 3 + 3 = 18.

pages 13-16
This array shows 3 rows of 4.
3 × 4 = 12
Envision Math Common Core Grade 3 Answers Topic 1 Understand Multiplication and Division of Whole Numbers 70.8
This array shows 4 rows of 3.
4 × 3 = 12
Envision Math Common Core Grade 3 Answers Topic 1 Understand Multiplication and Division of Whole Numbers 70.9
So, 3 × 4 = 4 × 3

Remember that the Commutative Property of Multiplication says you can multiply factors in any order and the product is the same.

Draw arrays and write the products.

Question 1.
2 × 5 = ____ 5 × 2 = ___

Answer:
2 x 5 = 10 and 5 x 2 = 10.

Explanation:
In the above-given question,
given that,
the number of rows = 2.
number in each column = 5.
2 x 5 = 10.
we can use commutative property.
5 x 2 = 10.
2 + 2 + 2 + 2 + 2 = 10.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-32

Set D
pages 17-24

Two friends share 6 fruit snacks equally. How many fruit snacks does each friend get?
6 ÷ 2 = 3 fruit snacks
You can use repeated subtraction.
Envision Math Common Core Grade 3 Answers Topic 1 Understand Multiplication and Division of Whole Numbers 75.

Remember that division is an operation to find the number of equal groups or the number in each equal group.

Question 1.
Nine raisin boxes are shared by 3 children. Each child gets Envision Math Common Core Grade 3 Answers Topic 1 Understand Multiplication and Division of Whole Numbers 75.7 raisin boxes.

Answer:
9 / 3 = 3.

Explanation:
In the above-given question,
given that,
Nine raisin boxes are shared by 3 children.
9 – 3 = 6.
6 – 3 = 3.
3 – 3 = 0.
9 / 3 = 3.

Question 2.
12 ÷ 2 = ___

Answer:
12 / 2 = 6.

Explanation:
In the above-given question,
given that,
12 – 2 = 10.
10 – 2 = 8.
8 – 2 = 6.
6 – 2 = 4.
4 – 2 = 2.
2 – 2 = 0.
12 / 2 = 6.

Question 3.
10 ÷ 5 = ___

Answer:
10 / 5 = 2.

Explanation:
In the above-given question,
given that,
10 – 5 = 5.
5 – 5 = 0.
10 / 5 = 2.

Question 4.
25 ÷ 5 = ___

Answer:
25 / 5 = 5.

Explanation:
In the above-given question,
given that,
25 – 5 = 20.
20 – 5 = 15.
15 – 5 = 10.
10 – 5 = 5.
5 – 5 = 0.
25 / 5 = 5.

Question 5.
16 ÷ 4 = ___

Answer:
16 / 4 = 4.

Explanation:
In the above-given question,
given that,
16 – 4 = 12.
12 – 4 = 8.
8 – 4 = 4.
4 – 4 = 0.
16 / 4 = 4.

Question 6.
12 ÷ 3 = __

Answer:
12 / 3 = 4.

Explanation:
In the above-given question,
given that,
12 – 3 = 9.
9 – 3 = 6.
6 – 3 = 3.
3 – 3 = 0.
12 / 3 = 9.

Question 7.
24 ÷ 6 = ___

Answer:
24 / 6 = 4.

Explanation:
In the above-given question,
given that,
24 – 6 = 18.
18 – 6 = 12.
12 – 6 = 6.
6 – 6 = 0.
24 / 6 = 4.

Set E
pages 25 – 28
Think about these questions to help you use appropriate tools strategically.

Thinking Habits
Which tools can I use?
Why should I use this tool to help me solve the problem?
Is there a different tool I could use?
Am I using the tool appropriately?
Envision Math Common Core Grade 3 Answers Topic 1 Understand Multiplication and Division of Whole Numbers 100

Remember that you can use digital tools.

Sam makes enough muffins to give 8 of her friends 3 muffins each. Each tray holds 6 muffins. How many trays does she need?

Question 1.
Choose a tool to represent the problem. Explain why you chose that tool.

Answer:
The number of trays she needs = 16 trays.

Explanation:
In the above-given question,
given that,
Sam makes enough muffins to give 8 of her friends 3 muffins each.
Each tray holds 6 muffins.
8 / 3 = 2.6.
2.6 x 6 = 15.6.
so the number of trays she needs = 16 trays.

Question 2.
Solve. Explain how the tool helped.
Answer:

Topic 1 Assessment Practice

Question 1.
Jace drew a picture. Which multiplication expression represents the total number of circles?
Envision Math Common Core Grade 3 Answers Topic 1 Understand Multiplication and Division of Whole Numbers 80.10
A. 4 × 3
B. 4 × 1
C. 4 × 2
D. 4 × 8

Answer:
Option C is correct.

Explanation:
In the above-given question,
given that,
4 groups of 2.
2 + 2 + 2 + 2 = 8.
4 x 2 = 8.
so option C is correct.

Question 2.
Aidan has 2 turtles in each of 4 aquariums.
A. Write an equation that represents how many turtles Aidan has in all.
B. How many turtles does Aidan have in all?
Envision Math Common Core Grade 3 Answers Topic 1 Understand Multiplication and Division of Whole Numbers 85.1 turtles

Answer:
A. 4 x 2.
B. The number of turtles do Aidan has in all = 8.

Explanation:
In the above-given question,
given that,
Aidan has 2 turtles in each of 4 aquariums.
4 groups of 2.
2 + 2 + 2 + 2 = 8.
4 x 2 = 8.
so the number of turtles do aidan have in all = 8.

Question 3.
Noah’s watering can holds enough water for watering 4 plants. How many plants can Noah water if he fills his watering can 3 times?
Envision Math Common Core Grade 3 Answers Topic 1 Understand Multiplication and Division of Whole Numbers 85.1 plants

Answer:
The number of plants can Noah water if he fills his watering can 3 times = 12 plants.

Explanation:
In the above-given question,
given that,
Noah’s watering can holds enough water for watering 4 plants.
4 x 3 = 12.
that means she can water 3 plants one time.
3 + 3 + 3 = 12.
so the number of plants can Noah water = 12 plants.

Question 4.
Megan organized her photos in this array. What is the multiplication equation for the array? Draw a different array that has the same factors.
Envision Math Common Core Grade 3 Answers Topic 1 Understand Multiplication and Division of Whole Numbers 85.2

Answer:
The different array that has the same factors = 3 and 4.

Explanation:
In the above-given question,
given that,
Megan organized her photos in this array.
4 x 3.
3 + 3 + 3 + 3 = 12.
4 x 3 = 12.
we can write it as 3 x 4.
4 + 4 + 4 = 12.
3 x 4 = 12.
so the new array = 3 x 4.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-33

Question 5.
Josiah kicked six 3-point field goals in his football game. Which multiplication equation represents the number of points that Josiah scored?
A. 6 × 3 = 18
B. 6 × 1 = 6
C. 3 × 3 = 9
D. 6 × 6 = 36

Answer:
Option A is correct.

Explanation:
In the above-given question,
given that,
Josiah kicked six 3-point field goals in his football game.
six groups of 3.
3 + 3 + 3 + 3 + 3 + 3 = 18.
6 x 3 = 18.
so option A is correct.

Question 6.
Teresa is growing 2 rows of tomato plants, with 4 plants in each row. Write an expression that represents the total number of plants. Find the total number of plants.

Answer:
The total number of plants = 8.

Explanation:
In the above-given question,
given that,
Teresa is growing 2 rows of tomato plants, with 4 plants in each row.
2 groups of 4 plants.
2 x 4 = 8.
2 + 2 + 2 + 2 = 8.
so the number of plants = 8.

Question 7.
Ann has 24 tennis balls. She separates them equally into 3 different baskets.
A. Write a division equation that shows the number of tennis balls in each basket.
B. How many tennis balls are in each basket?
Envision Math Common Core 3rd Grade Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 86.3 tennis balls

Answer:
A. 24 / 3 = 8.
B. The number of tennis balls in each basket = 8 balls.

Explanation:
In the above-given question,
given that,
Ann has 24 tennis balls.
She separates them equally into 3 different baskets.
24 / 3 = 8.
8 + 8 + 8 = 24.
24 / 8 = 3.
so the number of tennis balls in each basket = 8 balls.

Question 8.
Mikael gave 3 pencils each to 7 of his friends. Which equation represents the number of pencils Mikael gave away?
A 3 × 1 = 3
B. 7 × 1 = 7
C. 7 × 3 = 21
D. 3 × 3 = 9

Answer:
The number of pencils Mikael gave away = 21.

Explanation:
In the above-given question,
given that,
Mikael gave 3 pencils each to 7 of his friends.
3 x 7 = 21.
7 + 7 + 7 = 21.
so option C is correct.

Question 9.
Al needs to put 9 hats in each box. He has 45 hats. Write and solve an equation that shows how many boxes Al can fill.

Answer:
The number of boxes AI can fill =  45 hats.

Explanation:
In the above-given question,
given that,
Al needs to put 9 hats in each box.
he has 45 hats.
45 / 9 = 5.
9 x 5 = 45.
9 + 9 + 9 + 9 + 9 = 45.
so the number of boxes AI can fill = 45 hats.

Question 10.
There are 48 students in a class. The teacher puts them into 8 equal groups. How many students are in each group?
Envision Math Common Core 3rd Grade Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 87.1 students

Answer:
The number of students in each group = 6 students.

Explanation:
In the above-given question,
given that,
There are 48 students in a class.
the teacher puts them into 8 equal groups.
48 / 8 = 6.
6 x 8 = 48.
so the number of students in each group = 6 students.

Question 11.
Saima makes 14 muffins to give to her friends. She wants to give 2 muffins to each friend at her party. How many friends can Saima invite to her party? Explain how Saima can figure out how many friends to invite.

Answer:
The number of friends can Saima invite to her party = 7 friends.

Explanation:
In the above-given question,
given that,
Saima makes 14 muffins to give to her friends.
She wants to give 2 muffins to each friend at her party.
14 / 2 = 7.
she figures out 7 friends for her party.
2 + 2 + 2 + 2 + 2 + 2 + 2 = 14.
so the number of friends can Saima invite to her party = 7 friends.

Question 12.
Which of the following contexts does the expression 15 ÷ 3 represent?
A. 15 books arranged equally on 3 shelves
B. 15 books arranged equally on 15 shelves
C. 3 books arranged equally on 15 shelves
D. 3 books arranged equally on 3 shelves

Answer:
Option A is correct.

Explanation:
In the above-given question,
given that,
15 books arranged equally on 3 shelves.
15 / 3 = 5.
5 + 5 + 5 = 15.
on each shelf, we can arrange 5 books.
so option A is correct.

Topic 1 Performance Task

Sticker Collection
Jamie saved money to buy a sticker album.
The money he has saved each week is shown in the table.
Sticker Prices

  • Green sticker albums cost $6.
  • Blue sticker albums cost $9.
  • Yellow sticker albums cost $12.
  • Stickers cost $1 for 3 stickers.

Envision Math Common Core 3rd Grade Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 87.2

Use the Money Saved Each Week table to answer Exercise 1.

Question 1.
How much money has Jamie saved after 4 weeks? Write a multiplication equation to solve.

Answer:
The money Jamie saved after 4 weeks = $12.

Explanation:
In the above-given question,
given that,
Jamie saved in ist week = $3.
he saved in 2nd week = $3.
he saved in 3rd week = $3.
he saved in 4th week = $3.
3 + 3 + 3 + 3 = 12.
4 x $ 3 = $12.
so the money Jamie saved after 4 weeks = $12.

Use the Sticker Prices list to answer Exercises 2-4.

Question 2.
Jamie divides his money into two equal parts. Jamie spends 1 part on a sticker album. Which of the albums can Jamie buy?

Answer:
Jamies buy a green sticker album.

Explanation:
In the above-given question,
given that,
Jamie divides his money into two equal parts.
Jamie spends 1 part on a sticker album.
12 / 2 = 6.
the cost of the green sticker = $6.
so Jamies buy a green sticker album.

Question 3.
Jamie spends the other part of his money on stickers. How many stickers can Jamie buy?

Answer:
Jamie buys 3 stickers.

Explanation:
In the above-given question,
given that,
Jamie spends the other part of his money on stickers.
he buys 3 stickers for $1.
so Jamies buys 3 stickers.

Question 4.
After spending his money, Jamie decides that he wants a second album. He plans to save $3 per week until he can also buy a blue sticker album. How many weeks does Jamie need to save money?

Answer:
The number of weeks Jamie needs to save money = 3 weeks.

Explanation:
In the above-given question,
given that,
Jamie decides that he wants a second album.
He plans to save $3 per week.
the second album is the blue album.
the blue album costs $9.
so he wants to save 3 weeks.
3 + 3 + 3 = 9.

Use the Sticker Arrays table to answer Exercise 5.

Question 5.
Jamie wants to organize his stickers into arrays on a page of the album. Jamie started to make a table to show three ways he could do this.
Envision Math Common Core 3rd Grade Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 87.3
Part A
Draw arrays to show the two ways Jamie planned to organize his stickers.
Envision Math Common Core 3rd Grade Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 95.2
Part B
Draw an array to show another way Jamie could organize his stickers.
Complete the Sticker Arrays table for Way 3.
Envision Math Common Core 3rd Grade Answer Key Topic 1 Understand Multiplication and Division of Whole Numbers 95.3

Answer:
A. 6 x 3 and 2 x 9.
B. 3 x 6.

Explanation:
In the above-given question:
given that,
in way 1 number of rows = 6.
number of columns = 3.
6 x 3 = 18.
in way 2 number of rows = 2.
the number of columns = 9.
2 x 9 = 18.
in way 3 number of rows = 3.
number of columns = 6.
3 x 6 = 18.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-34
Question 6.
Write multiplication equations for each array to check that Jamie uses all of his stickers in each plan. Are there two ways that show the same factors? Explain.

Answer:
Yes, there are two ways that show the same factors.

Explanation:
In the above-given question,
given that,
way 1 and way 2 are the same.
3 x 6 and 6 x 3.
3 x 6 = 18.
3 and 6 are the factors.
6 x 3 = 18.
6 and 3 are the factors.
so there are two ways that show the same factors.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-1-Undarstand Multiplication and Division of Whole Numbers-35

enVision Math Common Core Grade 2 Answer Key Topic 13 Shapes and Their Attributes

Practice with the help of enVision Math Common Core Grade 2 Answer Key Topic 13 Shapes and Their Attributes regularly and improve your accuracy in solving questions.

enVision Math Common Core 2nd Grade Answers Key Topic 13 Shapes and Their Attributes

Essential Question:
How can shapes be described, compared, and broken into parts?
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 1

enVision STEM Project: All About Shape
Find Out Draw pictures of tools used for gardening, cooking, or fixing. Describe the shape of each tool. Tell how the shape of each tool helps it work.
Journal: Make a Book Show your work in a book. In your book, also:

  • Choose a tool that you use at school. Tell how the shape of the tool helps it work.
  • Draw and describe polygon shapes.

Review What You Know

Vocabulary
Question 1.
Circle the shape that has 6 sides.
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 2
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-13-Shapes-and-Their-Attributes-2
The polygon with 6 sides is called a hexagon.
The blue figure has 5 sides and the green figure has 6 sides.
So, the answer is a green figure.

Question 2.
Circle each plane shape. Put a box around each solid figure.
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 3
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-13-Shapes-and-Their-Attributes-3

Question 3.
Put a box around the circle that shows fourths.
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 4
Answer:
The first figure is divided into four parts.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-13-Shapes-and-Their-Attributes-4

Basic Facts
Question 4.
Write each sum.
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 5
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-13-Shapes-and-Their-Attributes-5

Question 5.
Write each difference.
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 6
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-13-Shapes-and-Their-Attributes-6

Math Story
Question 6.
Edna has a bookcase with 5 shelves. She places 5 books in a row on each shelf. Write an equation that shows how many books Edna has in all.
Answer:
Given,
Edna has a bookcase with 5 shelves.
She places 5 books in a row on each shelf.
5 × 5 = 25
Thus there are 25 books in all.

Pick a Project

PROJECT 13A
What shapes can you find in a tile design?
Project: Create a Tile Design
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 7

PROJECT 13B
How do architects design a house?
Project: Draw Your Dream Building
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 8

PROJECT 13C
What national landmarks are in your state?
Project: Build a Landmark
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 9

3-ACT MATH PREVIEW

Math Modeling Straw Shaped
Before watching the video, think: What can you build with straws? What kind of shapes? How can you compare those shapes?
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 10

Lesson 13.1 2-Dimensional Shapes

Solve & Share
Look at the picture. How many triangles can you find? Trace each triangle. Be ready to explain how you know you have found them all.
I can … recognize shapes by how they look.
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 11
________ triangles

Answer: 10 triangles

Visual Learning Bridge
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 12

Convince Me! How do sides and vertices help you name a plane shape?

Guided Practice

Match each shape to its name.
Question 1.
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 13

Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-13-Shapes-and-Their-Attributes-13

Tell how many sides and vertices. Name each shape.
Question 2.
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 14
________ sides
________ vertices
Shape: __________
Answer:
4 sides
4 vertices
Shape: Quadrilateral
The above figure is a quadrilateral with four sides and four vertices.

Question 3.
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 15
________ sides
________ vertices
Shape: __________
Answer:
5 sides
5 vertices
Shape: Pentagon
The above figure is a pentagon with five sides and five vertices.

Independent Practice

Match each shape to its name.
Question 4.
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 16
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-13-Shapes-and-Their-Attributes-16

Question 5.
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 17
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-13-Shapes-and-Their-Attributes-17

Draw the shape. Tell how many sides and vertices.
Question 6.
Quadrilateral
________ sides
________ vertices
Answer:
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 14

4 sides
4 vertices
A quadrilateral is a regular polygon with four sides and four vertices.

Question 7.
Hexagon
________ sides
________ vertices
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-13-Shapes-and-Their-Attributes-14
6 sides
6 vertices
A hexagon is a polygon with 6 sides and 6 vertices.

Question 8.
Triangle
________ sides
________ vertices
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-13-Shapes-and-Their-Attributes-18
3 sides
3 vertices
A triangle is a polygon with three sides and three vertices.

Question 9.
Higher Order Thinking Bianca drew a triangle and a pentagon. How many sides and vertices did she draw in all? Draw the shapes.
________ sides
________ vertices
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-13-Shapes-and-Their-Attributes-18
3 sides
3 vertices
A triangle is a polygon with three sides and three vertices.
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 15
5 sides
5 vertices
The above figure is a pentagon with five sides and five vertices.

Problem Solving

Solve each problem.
Question 10.
Model Marcos has 4 toothpicks. He places them as shown. What shape can Marcos make if he adds one more toothpick?
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 18
Answer:
If Marcos adds one more toothpick it becomes a pentagon.

Question 11.
Vocabulary Connect all the dots to make two shapes that have vertices. Name the shapes that you make.
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 19
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-13-Shapes-and-Their-Attributes-19

Question 12.
Higher Order Thinking Randall said that a square is a quadrilateral. Susan said that a square is a square, so it is not a quadrilateral. Who is correct? Explain.
Answer:
A square is a square and also a quadrilateral. So, Randall is correct.

Question 13.
Assessment Practice Which shape is NOT a hexagon?
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 20
Answer: Option C has 5 sides so it is not a hexagon.
Thus the answer is option C.

Lesson 13.2 Polygons and Angles

Solve & Share
Look at the three plane shapes below. How are they alike? How are they different? Measure the length of the sides to help describe them. Name each shape.
I can … describe plane shapes by how they look.
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 21

Visual Learning Bridge
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 22

Convince Me! How many angles does this shape have? How many right angles? Name the shape.

Guided Practice

Write the number of angles and Practice then name the shape.
Question 1.
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 23
________ angles
Shape: _________
Answer:
5 angles
Shape: Pentagon

Explanation:
The above figure is a pentagon with five angles.

Question 2.
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 24
________ angles
Shape: _________
Answer:
5 angles
Shape: Pentagon

Explanation:
The above figure is a pentagon with five angles.

Question 3.
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 25
________ angles
Shape: _________
Answer:
6 angles
Shape: Hexagon

Explanation:
The above figure is a hexagon with six angles.

Question 4.
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 26
________ angles
Shape: _________
Answer:
3 angles
Shape: Triangle

Explanation:
The above figure is a triangle with three angles.

Independent Practice

Write the number of angles and then name the shape.
Question 5.
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 27
________ angles
Shape: _________
Answer:
5 angles
Shape: Pentagon

Explanation:
The above figure is a pentagon with five angles.

Question 6.
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 28
________ angles
Shape: _________
Answer:
6 angles
Shape: Hexagon

Explanation:
The above figure is a hexagon with six angles.

Question 7.
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 29
________ angles
Shape: _________
Answer:
4 angles
Shape: Quadrilateral

Explanation:
The above figure is a Quadrilateral with four angles.

Question 8.
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 30
________ angles
Shape: _________
Answer:
6 angles
Shape: Hexagon

Explanation:
The above figure is a hexagon with six angles.

Question 9.
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 31
________ angles
Shape: _________
Answer:
4 angles
Shape: Quadrilateral

Explanation:
The above figure is a Quadrilateral with four angles.

Question 10.
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 32
________ angles
Shape: _________
Answer:
5 angles
Shape: Pentagon

Explanation:
The above figure is a pentagon with five angles.

Question 11.
Higher Order Thinking Draw a polygon with 2 right angles and 2 angles that are not right angles. Name the shape you draw.
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 33
Answer:
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 30

Problem Solving

Solve each problem.
Question 12.
Be Precise Which plane shapes are sewn together in the soccer ball?
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 34
Answer: Pentagon and hexagon are seen together in the soccer ball.

Question 13.
enVision® STEM Bees make honeycomb. The honeycomb shape uses less wax than other shapes. Name the shape. Tell how many angles the shape has.
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 35
Answer:
Given,
Bees make honeycomb. The honeycomb shape uses less wax than other shapes.
The shape of the honeycomb is the hexagon.

Question 14.
Higher Order Thinking Draw a polygon shape that has 7 angles. How many sides does the polygon have? How many vertices does it have?
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-13-Shapes-and-Their-Attributes-20

Question 15.
Assessment Practice Name the shape of the sign below. Write 3 things that describe the shape.
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 36
Answer:
The shape of the above sign is a pentagon.

Lesson 13.3 Draw 2-Dimensional Shapes

Solve & Share
Draw a polygon with 3 sides that are the same length. Then draw a polygon with 3 sides that are different lengths. Measure the lengths of the sides you drew. Tell 4 ways the shapes are alike.
I can … draw polygon shapes.
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 37

Visual Learning Bridge
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 38

Convince Me! Draw a quadrilateral with 4 sides that are the same length and with 4 right angles. Write 2 names for the quadrilateral.

Guided Practice

Draw each shape. Complete the sentences.
Question 1.
Draw a polygon with 3 vertices.
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 39
The polygon also has _______ sides.
The polygon is a ________
Answer:
The polygon also has three sides.
The polygon is a triangle.

Question 2.
Draw a polygon with 6 sides.
The polygon also has _______ angles.
The polygon is a _______
Answer:
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 25
The polygon also has six angles.
The polygon is a hexagon.

Independent Practice

Draw each shape. Complete the sentences.

Question 3.
Draw a polygon with 3 vertices and I right angle.
The polygon also has _______ sides.
The polygon is a _______
Answer:
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 26
The polygon also has three sides.
The polygon is a right angle.

Question 4.
Draw a quadrilateral with opposite sides that are the same length.
The polygon also has _______ vertices.
The polygon is a _______
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-13-Shapes-and-Their-Attributes-21
The polygon also has four vertices.
The polygon is a Rectangle.

Question 5.
Draw a polygon with 4 sides that are the same length.
The polygon also has _______ angles.
The polygon is a _______
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-13-Shapes-and-Their-Attributes-22
The polygon also has four angles.
The polygon is a square.

Question 6.
Draw a polygon with 4 sides that are different lengths.
The polygon also has _______ angles.
The polygon is a _______
Answer:
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 31
The polygon also has four angles.
The polygon is a quadrilateral

Question 7.
Draw a polygon with 5 vertices and 3 sides that are the same length.
The polygon also has _______ sides in all.
The polygon is a _______
Answer:
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 27
The polygon also has five sides in all.
The polygon is a pentagon

Question 8.
Higher Order Thinking Can you draw a polygon with 3 vertices and 4 sides? Explain.
Answer: No

Problem Solving

Solve the problems below.
Question 9.
Be Precise Draw a rectangle with 4 equal sides.
What is another name for this shape?
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-13-Shapes-and-Their-Attributes-22
The polygon also has four angles.
The polygon is a square.

Question 10.
Draw 3 shapes. The first shape is a quadrilateral. The number of vertices in each shape increases by one.
Name the third shape. __________
Answer:
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 32
The polygon has five sides and five vertices.
The name of the shape is a pentagon.
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 25
The polygon also has six angles.
The polygon is a hexagon.

Question 11.
Higher Order Thinking The owner of Joe’s Fish Market wants a new sign. He wants the sign to have curved sides. Draw a sign for Joe’s Fish Market.
Is the sign a polygon? Explain.
Answer: No the sign of Joe’s fish market is not a polygon.

Question 12.
Assessment Practice David drew two different polygons. One of the polygons was a square. If David drew 9 sides and 9 vertices in all, what other polygon did David draw?
Envision Math Common Core 2nd Grade Answer Key Topic 13 Shapes and Their Attributes 40
Answer: option D

Lesson 13.4 Cubes

Solve & Share
m Describe the two shapes in 4 or more ways. Tell how they are different and how they are the same. Use a tool to include measurements in your description.
I can … draw cubes and describe how they look.
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 41

Visual Learning Bridge
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 42

Convince Me! What solid figure has 6 equal faces? What is the shape of each face?

Guided Practice

Circle the cubes in the group of shapes. Be ready to explain how you know they are cubes.
Question 1.
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 43
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-13-Shapes-and-Their-Attributes-43

Question 2.
Use the dot paper. Draw a cube.
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 44
Answer:
A symmetrical three-dimensional shape, either solid or hollow contained by six equal squares

Independent Practice

Decide if the shape is a cube. Then draw a line from each shape to cube or NOT a cube.
Question 3.
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 45
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-13-Shapes-and-Their-Attributes-45

Question 4.
Trace the cube shown below.
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 46
How many faces can you see?
________ faces
Answer: 6 faces

Algebra Use what you know about cubes to write an equation and solve each problem.
Question 5.
How many vertices do these two cubes have in all?
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 47

Answer: 8 + 8 = 16
Thus there are 16 vertices in two cubes.

Question 6.
How many faces do these two cubes have in all?
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 48
Answer:
6 + 6 = 12
Thus there are 12 faces in two cubes.

Problem Solving

Use what you know about cubes to solve each problem.
Question 7.
Explain Scott is holding a solid figure with 6 equal faces, 12 edges, and 8 vertices. Scott says the figure is a cube. Carmen says the figure is a square. Who is correct? Explain.
Answer:
Cube or Cuboid has 6 equal faces, 12 edges, and 8 vertices.

Question 8.
Vocabulary Circle the vocabulary word that completes the sentence.
vertices
faces
edges
A cube has 6 _________.
Answer: A cube has 6 faces.

Question 9.
Higher Order Thinking Use a place-value ones cube or another solid cube. Look at the cube as you turn it. Turn the cube in any direction.
What is the greatest number of faces you can see at one time? Explain.
Answer: Number of faces is 4

Question 10.
Assessment Practice Complete the sentences about a cube.
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 49
A cube is a solid ________.
A cube has ________ equal faces, ________ vertices, and _______ edges.
Answer:
A cube is a solid shape.
A cube has 6 equal faces, 8 vertices, and 12 edges.

Lesson 13.5 Equal Shares

Solve & Share
How many equal squares cover this rectangle? How could you show this with an addition equation?
I can … cover rectangles with equalsize squares and count to find the total number of them.
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 50
__________ equal squares
Equation: _________

Answer:
20 equal squares
Equation: 4 × 5 = 20

Visual Learning Bridge
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 51

Convince Me! Explain how you can cover a rectangle with equal-sized squares to help you find the total number of them.

Guided Practice

Solve.
Question 1.
Use square tiles to cover the rectangle. Trace the tiles. Column 1 is done for you.
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 52

Answer:
By using the above diagram square tiles are filled in rows and columns
The number of squares in a rectangle is equal to the number of rows into the number of columns
3 x 6 = 18

Question 2.
Count and add. How many squares cover the rectangle?
Add by rows: ________ + ________ + ______ = _______
Add by columns:
________ + ________ + ______ + ________ + ________ + ______ = _______

Answer:
6 squares cover the rectangle

Explanation:
Add by rows: 6+6+6=18
Add by columns:
3+3+3+3+3+3=18

Independent Practice

Use square tiles to cover each rectangle. Trace the tiles. Count the squares.
Question 3.
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 53
Add by rows: ________ + ________ + ________ + ______ = _______
Add by columns:
________ + ________ + ______ + ________ + ________ = _______
Answer:
By using the above diagram square tiles are filled in rows and columns
The number of squares in a rectangle is equal to the number of rows into the number of columns.
Add by rows: 5+5+5+5=20
Add by columns: 4+4+4+4+4=20

Question 4.
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 54
Add by rows: ________ + ________ + ________ + ______ = _______
Add by columns:
________ + ________ + ______ + ________ + ________ = _______
Answer:
By using the above diagram square tiles are filled in rows and columns
The number of squares in a rectangle is equal to the number of rows into the number of columns.
Add by rows: 5+5+5+5=20
Add by columns: 4+4+4+4+4=20

Question 5.
Number Sense Draw a rectangle that is made up of 6 equal squares.
Answer:
A rectangle is drawn by 6 equal squares.

Problem Solving

Solve each problem.
Question 6.
Look for Patterns Lisa bakes cornbread. She cuts it into equal square pieces. How many equal squares do you see? Write two equations to show the total number of square pieces.
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 55
Rows: _____ + _____ + _____ + _____ + _____ + _____ = _____ pieces
Columns: _____ + _____ + _____ + _____ = _____ pieces
Answer:
By using the above diagram square tiles are filled in rows and columns
Number of squares in a rectangle is equal to number of rows into number of columns
Explanation:
Add by rows: 4+4+4+4+4+4=24 pieces
Add by columns: 6+6+6+6=24 pieces

Question 7.
Vocabulary Label the columns and the rows for the large square below.
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 56
Answer: number of rows into a number of columns 3×3=9

Question 8.
Higher Order Thinking Look at the large square in Item 7. What do you notice about the number of rows and the number of columns? Explain.
Answer:
If you take a square with item 7
The number of rows is 7 and the number of columns is 7
7 x 7 = 49

Question 9.
Assessment Practice Count the equal squares in the rows and columns of the rectangle. Then use the numbers on the cards to write the missing numbers in the equations.
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 57
Row = _____ + ______ = ______
Columns = ______ + ______ + ______ + ______ + ______ + ______ + ______ = ______
Answer:
By using the above diagram square tiles are filled in rows and columns
Number of squares in a rectangle is equal to number of rows into number of columns
Explanation:
Rows =7+7=14
Columns = 2+2+2+2+2+2+2=14

Lesson 13.6 Partition Shapes

Solve & Share
Fold a paper square one time to make equal shares. How many equal shares are there? Fold a different square 2 times to make equal shares. How many equal shares are there? Draw your fold lines on the squares below. What can you say about the number of folds and the number of equal shares?
I can … show circles and rectangles in halves, thirds, and fourths.
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 58

Visual Learning Bridge
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 59

Convince Me! Show this rectangle with three equal shares. How many thirds is one share? How many thirds is the whole rectangle?
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 60

Answer: For example if you take a kerchief of square shape and fold it once it becomes 2 equal shares and 2 fold it turns to 4 shares.

Guided Practice

Solve each problem.
Question 1.
Show each square in halves. Show four different ways.
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 61

Answer:
The first square is divided diagonally,
The second square is divided vertically,
The third square is divided diagonally,
The fourth square is divided horizontally.

Question 2.
Tell what part of the whole each equal share is. Write a half of, a third of, or a fourth of.
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 62
Answer:

Rectangle a fourth
Circle a third
Square a half

Explanation:
From the above figure rectangle is 1/4 th of equal share,
Circle is 1/3 rd and the square is 1/2.

Independent Practice

Show each shape with the number of equal shares given. Show 2 ways. Then complete the sentences.
Question 3.
3 equal shares
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 63
Each share is ________ the whole.
Each whole is ______________.
Answer:

The first rectangle is divided vertically
The second rectangle is divided horizontally.

Explanation:
Each share is one third the whole
Each whole is one third

Question 4.
4 equal shares
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 63
Each share is _________ the whole.
Each whole is __________.
Answer:
The first rectangle is divided vertically
The second rectangle is divided horizontally.

Explanation:
Each share is one fourth the whole
Each whole is one fourth

Question 5.
2 equal shares
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 64
Each share is _________ the whole.
Each whole is __________.
Answer:
The first circle is divided vertically
The second circle is divided horizontally.

Explanation:
Each share is one half the whole
Each whole is one half

Question 6.
Higher Order Thinking Draw what comes next.
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 65
Answer:

Problem Solving

Solve each problem.
Question 7.
Model Leon cut a waffle into halves. Draw lines to show 3 different ways he could have cut the waffle.
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 66
Answer:
The first square is divided vertically
the second square is divided horizontally
The third square is divided diagonally.

Question 8.
enVision® STEM Tina is planting a garden. She wants to have equal parts for beans, for tomatoes, and for peppers. Draw a picture of how she could plant her garden.
Answer:
Consider the garden in rectangle shape
One third is for beans and the second part is for tomatoes and the last part is for peppers.

Question 9.
Higher Order Thinking Draw lines on the picture to solve the problem. 4 friends want to share a watermelon. How could they cut the watermelon so each friend gets an equal share?
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 67
Answer:
Each friend will get __________.
Answer:
Each friend will get one fourth

Question 10.
Assessment Practice Matt wants a flag that shows fourths. Which flags could Matt use? Choose all that apply.
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 68
Answer:
The first three matt can use as flags

Lesson 13.7 Equal Shares, Different Shapes

Solve & Share
Use a crayon to show 4 equal shares of this pizza. Compare your answer with a partner. Did you both make 4 equal shares? Do your shares look the same?
I can … make equal shares that do not have the same shape.
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 69

Answer:
In anne’s pizza cutting she made into 4 equal parts as squares
In Mark’s pizza cutting he made 4 equal parts as rectangles.
Both ways are correct.

Visual Learning Bridge
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 70

Convince Me! How can you check to make sure all of the shares are equal?

Guided Practice

Draw lines to show 2 equal shares. Each way should be different.
Question 1.
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 71

Answer: The first rectangle is divided horizontally
The second is divided vertically.

Question 2.
How many squares are in each equal share of the rectangles?
Answer:
In a rectangle, if it is divided into halves the shares will be two equal.

Question 3.
Describe the equal shares and the whole.
Each share is a half of the whole.
Each whole is two halves.

Answer: When you divide a whole in two you get equal shares.

Independent Practice

Draw lines in each rectangle to show 4 equal shares. Each way should be different. Then answer the questions.
Question 4.
Show equal shares that are the same shape.
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 72
Show equal shares that are different shapes.
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 73
Answer:
In the above two rectangular boxes one is divided equally and the other is divided in 3 parts but not equal.

Question 5.
How many squares are in each equal share in Item 4?
Answer:
In a square if we divide by 4 then the squares is four

Question 6.
Describe the equal shares and the whole in Item 4.
Each share is ___________ the whole.
Each whole is ___________.
Answer:
Each share is one fourth the whole
Each whole is one fourth

Draw lines to show 3 equal shares in two different ways.
Question 7.
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 74
Answer:
The first one is divided vertically and the other is divided horizontally.

Question 8.
Higher Order Thinking How can equal shares in a rectangle have different shapes?
Answer:
The first figure is having vertical rectangular
The second is having square
The third is having horizontal rectangles.

Problem Solving

Solve each problem.
Question 9.
Allen wants to share this pan of corn bread with 3 friends. Allen and his friends will each get an equal share.
How many pieces will be in each share?
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 75
___________ pieces
Answer:
Allen wants to share this pan of cornbread with 3 friends. If you cut the bread horizontally.
Each friend get 4 pieces

Question 10.
Explain Greg says that equal shares can be different in shape and size. Is Greg correct? Explain.
Answer:
The above figure explains that grey says that equal shares can be different in shape and size.
If the shape is the same.

Question 11.
Higher Order Thinking Donna drew the line in this rectangle to make 2 equal shares. Are the shares equal? Why or why not?
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 76
Answer:
The above figure is divided equally and has equal shares: the first half is having 10 boxes and the second is also having 10 boxes.

Question 12.
Assessment Practice Meg shows a rectangle with 3 equal shares that are NOT the same shape. Which could be Meg’s rectangle?
Envision Math Common Core 2nd Grade Answers Topic 13 Shapes and Their Attributes 77
Answer:
Meg shows a rectangle with 3 equal shares that are NOT the same shape 4 is Meg’s rectangle.

Lesson 13.8 Problem Solving

Repeated Reasoning
Solve & Share
Design two different flags. Draw 15 equalsize squares in each flag. Use rows and columns.
Make three equal shares of different colors in each flag. Then write an equation for each flag to show the total number of squares.
I can … use repeated reasoning to show rectangles with rows and columns and create designs with equal shares.
Envision Math Common Core Grade 2 Answer Key Topic 13 Shapes and Their Attributes 78
Thinking Habits Does something repeat in the problem? How can the solution help me solve another problem?
Envision Math Common Core Grade 2 Answer Key Topic 13 Shapes and Their Attributes 79

Visual Learning Bridge
Envision Math Common Core Grade 2 Answer Key Topic 13 Shapes and Their Attributes 80

Convince Me! How do you know each share in Design 2 is a fourth of the whole square?

Answer: If we do by equation he has to give 4 squares hence the design 2 is correct.

Guided Practice

Solve the problem. Use crayons to color. Practice
Question 1.
Hamal is painting a design. The design must have 3 colors with an equal share for each color. Create two possible designs for Hamal.
Envision Math Common Core Grade 2 Answer Key Topic 13 Shapes and Their Attributes 81

Answer:
In design two by counting the squares used 3 colors in design 1 by columns we colored.
Each share has 4 small squares so, any shape with 4 small squares is an equal share.
I can make shares that are the same shapes, these fourths are all squares.
In other design, I used different shapes for the shares

Independent Practice

Solve each problem. Use crayons to color. Explain your work.
Question 2.
Marie wants to put a rectangular design on a T-shirt. The design must have 4 colors with an equal share for each color. Create two possible designs for Marie.
Envision Math Common Core Grade 2 Answer Key Topic 13 Shapes and Their Attributes 82
Answer:
Each share has 4 small squares so, any shape with 4 small squares is an equal share.
I can make shares that are the same shapes, these fourths are all squares.
In other designs I used different shapes for the shares.

Question 3.
Grant wants to put a circle design on his toy car. The design must have 3 colors with an equal share for each color. Create two possible designs for Grant.
Envision Math Common Core Grade 2 Answer Key Topic 13 Shapes and Their Attributes 83
Answer:
In circles this is not possible.

Problem Solving

Performance Task
Tile Design Ms. Walton created this rectangular file design. What share of the design is orange? What share of the design is yellow? How many shares is the whole design? How many thirds is the whole?
Envision Math Common Core Grade 2 Answer Key Topic 13 Shapes and Their Attributes 84
Question 4.
Make Sense How does Ms. Walton’s design show equal shares? Explain.
Answer:
Each share has 4 small squares so, any shape with 4 small squares is an equal share.
I can make shares that are the same shapes, these fourths are all squares.
In another design I used different shapes for the shares.

Question 5.
Reasoning What share of the design is orange? What share of the design is yellow? How many shares is the whole design? How many thirds is the whole?
Answer:
Ms.Walton created this rectangular tile design one third of the design is orange two-third the design is yellow and three-thirds is the whole.

Question 6.
Generalize Copy the tile design above onto this grid. Then color it orange and yellow to match the design shown above.
Envision Math Common Core Grade 2 Answer Key Topic 13 Shapes and Their Attributes 85
How did you copy the design? Describe one or two shortcuts you used.
Answer:
Number of squares is 12

Explanation
I did it by equating the number of rows into the number of columns. By square count, we can do it

Topic 13 Fluency Practice Activity

Follow the path
Find each sum or difference. Then color a path from Start to finish. Follow the sums and differences that are even numbers. You can only move up, down, right, or left.
I can …add and subtract within 100.
Envision Math Common Core Grade 2 Answer Key Topic 13 Shapes and Their Attributes 86

Topic 13 Vocabulary Review

Understand Vocabulary

Write always, sometimes, or never.
Word List
• angle
• hexagon
• cube
• pentagon
• edge
. polygon
• equal shares
• quadrilateral
• face
• right angle
• fourths
• thirds
• halves
• vertex

Question 1.
A cube has exactly 4 faces. _________
Answer: Always

Question 2.
A right angle forms a square corner. ___________
Answer: Always

Question 3.
Quadrilaterals are squares. ___________
Answer: Sometimes

Question 4.
A solid figure with faces has edges. ___________
Answer: Sometimes

Draw a line from each term to its example.
Question 5.
hexagon
Envision Math Common Core Grade 2 Answer Key Topic 13 Shapes and Their Attributes 87
Answer:

Question 6.
pentagon
Envision Math Common Core Grade 2 Answer Key Topic 13 Shapes and Their Attributes 88
Answer:

Question 7.
vertex
Envision Math Common Core Grade 2 Answer Key Topic 13 Shapes and Their Attributes 89
Answer:

Use Vocabulary in Writing
Question 8.
Tell how you can divide a square into two equal shares. Then tell how you can divide that same square into 3 equal shares. Use terms from the Word List.
Answer: Thirds

Topic 13 Reteaching

Set A

You can name a plane shape by its number of sides and vertices.
Envision Math Common Core Grade 2 Answer Key Topic 13 Shapes and Their Attributes 90

Write the number of sides and vertices. Name the shape.
Question 1.
Envision Math Common Core Grade 2 Answer Key Topic 13 Shapes and Their Attributes 91
_________ sides
_________ vertices
Shape: ________
Answer:
5 sides
five vertices
Pentagon

Question 2.
Envision Math Common Core Grade 2 Answer Key Topic 13 Shapes and Their Attributes 92
_________ sides
_________ vertices
Shape: ________
Answer:
5 sides
5 vertices
Pentagon

Set B

You can name a polygon by the number of its angles.
Envision Math Common Core Grade 2 Answer Key Topic 13 Shapes and Their Attributes 93

Write the number of angles. Then name the shape.
Question 3.
Envision Math Common Core Grade 2 Answer Key Topic 13 Shapes and Their Attributes 94
________ angles
Shape: ________
Answer:
Four angles
Rectangle and be a quadrilateral also

Question 4.
Envision Math Common Core Grade 2 Answer Key Topic 13 Shapes and Their Attributes 95
________ angles
Shape: ________
Answer:
3 angles
Triangle

Set C

You can draw a polygon with a given number of sides, vertices, or angles.
Draw a polygon with 4 sides. Two sides have different lengths.
Envision Math Common Core Grade 2 Answer Key Topic 13 Shapes and Their Attributes 96
Draw a polygon with 5 vertices.
Envision Math Common Core Grade 2 Answer Key Topic 13 Shapes and Their Attributes 97
Draw a polygon with 3 angles. One angle is a right angle.
Envision Math Common Core Grade 2 Answer Key Topic 13 Shapes and Their Attributes 98

Draw each polygon described.
Question 5.
6 sides
Answer:

Question 6.
3 vertices
Answer:

Question 7.
5 sides and 2 right angles
Answer:

Question 8.
8 angles
Answer:
An octagon is a polygon made up of 8 sides. It has eight angles. Octagon = Octa + gon where octa means eight and gon means sides

Set D

You can describe and draw cubes.
Envision Math Common Core Grade 2 Answer Key Topic 13 Shapes and Their Attributes 99

Question 9.
Cross out the shapes that are NOT cubes.
Envision Math Common Core Grade 2 Answer Key Topic 13 Shapes and Their Attributes 100
Answer:
A cube has 6 faces 12 edges and 8 vertices

Question 10.
Draw a cube. Use the dots to help you.
Envision Math Common Core Grade 2 Answer Key Topic 13 Shapes and Their Attributes 101
Answer:
Count by rows: 3 + 3 = 6
Count by columns: 2 + 2 + 2 = 6
6 squares cover the rectangle.

Set E

Reteaching Continued
You can cover a rectangle with squares.
Envision Math Common Core Grade 2 Answers Topic 13 Shapes and Their Attributes 102
Count by rows: 3 + 3 = 6
Count by columns: 2 + 2 + 2 = 6
6 squares cover the rectangle.

Use square tiles to cover the rectangle. Trace the tiles. Then count the squares.
Question 11.
Envision Math Common Core Grade 2 Answers Topic 13 Shapes and Their Attributes 103
__________ squares cover the rectangle.
Answer: 8 squares cover the rectangle

Set F

You can show circles and rectangles with equal shares.
Envision Math Common Core Grade 2 Answers Topic 13 Shapes and Their Attributes 104

Show each shape with the given number of equal shares. Show 2 ways.
Question 12.
halves Envision Math Common Core Grade 2 Answers Topic 13 Shapes and Their Attributes 105
Answer:
First circle is divided horizontally
Second circle is divided vertically.

Question 13.
thirds Envision Math Common Core Grade 2 Answers Topic 13 Shapes and Their Attributes 106
Answer:
First rectangle is divided horizontally in thirds
Second rectangle is divided vertically in thirds.

Question 14.
fourths Envision Math Common Core Grade 2 Answers Topic 13 Shapes and Their Attributes 107
Answer:
First square is divided horizontal and vertical in fourths
Second square is divided diagonally in fourths.

Set G

Equal shares can be different shapes. This is one way to show this rectangle with 3 equal shares.
Envision Math Common Core Grade 2 Answers Topic 13 Shapes and Their Attributes 108
Each equal share is 4 squares.

Draw lines to show 2 more ways these rectangles can have 3 equal shares.
Question 15.
equal shares that are NOT all the same shape
Envision Math Common Core Grade 2 Answers Topic 13 Shapes and Their Attributes 109
Answer:
The rectangle does not share the same shapes.

Question 16.
equal shares that are all the same shape
Envision Math Common Core Grade 2 Answers Topic 13 Shapes and Their Attributes 110
Answer:Divided by 4 squares

Set H

Thinking Habits Repeated Reasoning
Does something repeat in the problem?
How can the solution help me solve another problem?
Envision Math Common Core Grade 2 Answers Topic 13 Shapes and Their Attributes 111

Use the design shown. Create a different design with 3 equal shares.
Question 17.
Envision Math Common Core Grade 2 Answers Topic 13 Shapes and Their Attributes 112
Answer:
Each share has 4 small squares so, any shape with 4 small squares is an equal share.
I can make shares that are the same shapes, these fourths are all squares.
In other designs, I used different shapes for the shares.

Topic 13 Assessment Practice

Question 1.
Which polygons are pentagons?
Envision Math Common Core Grade 2 Answers Topic 13 Shapes and Their Attributes 113
Answer: 2 and 4 are pentagons

Question 2.
Rita draws a polygon. It has fewer than 8 sides and more angles than a square. Which shape did Rita draw?
A. triangle
B. rectangle
C. hexagon
D. quadrilateral
Answer:
Hexagon
A plane figure with six straight sides and angles.

Question 3.
Which rectangles are shown in fourths? Choose all that apply.
Envision Math Common Core Grade 2 Answers Topic 13 Shapes and Their Attributes 114
Answer: Option A, D

Question 4.
Draw a polygon with 4 angles. Make one angle a right angle. Then name the polygon.
Name: ______________
Answer: Quadrilateral

Question 5.
Is the polygon a quadrilateral? Choose Yes or No.
Envision Math Common Core Grade 2 Answers Topic 13 Shapes and Their Attributes 115
Answer: Quadrilateral will have 4 sides and 4 angles.

Question 6.
Mandy draws a polygon with 6 sides and 6 angles. Which shape did she draw?
A. pentagon
B. hexagon
C. octagon
D. quadrilateral
Answer:
A hexagon is a closed 2D shape that is made up of straight lines. It is a two-dimensional shape with six sides, six vertices, and six edges. The name is divided into hex, which means six, and gonia, which means corners.

Question 7.
Name the shape below. Write 3 things that describe the shape.
Envision Math Common Core Grade 2 Answers Topic 13 Shapes and Their Attributes 116
Answer:
Quadrilateral.

Explanation:
A quadrilateral has 4 sides, 4 angles, and 4 vertices.
A quadrilateral can be regular or irregular.
The sum of all the interior angles of a quadrilateral is 360°.

Question 8.
Draw the polygon described below.
Then complete the sentence.
I have 2 fewer sides than a pentagon. I have I less angle than a square. I have one right angle.
The shape is a __________.
Answer:Right-angled triangle

Explanation:
A right-angled triangle has 3 sides 3 angles and 3 vertices,
One less angle than a square,
2 fewer sides than a pentagon

Question 9.
Complete the sentence to name and describe the solid figure below.
Envision Math Common Core Grade 2 Answers Topic 13 Shapes and Their Attributes 117
A _______ has _______ faces, _______ vertices, has _______ edges.
Answer: A cube has 6 faces 8 vertices, has 12 edges.

Question 10.
Show this circle with 2 equal shares. Then complete the sentences.
Envision Math Common Core Grade 2 Answers Topic 13 Shapes and Their Attributes 118
Each share is a ________ of the whole.
The whole is _________ halves.
Answer:
Each share is half of the whole
The hole is 2 halves

Question 11.
Brad says there are only two ways to divide the same rectangle below into 3 equal shares. Do you agree? Use words and pictures to explain.
Envision Math Common Core Grade 2 Answers Topic 13 Shapes and Their Attributes 119
Answer: The above figure shows Brad was wrong.

Question 12.
Count the number of squares in the rows and columns of the rectangle. Use the numbers on the cards to write the missing numbers in the equations.
Envision Math Common Core Grade 2 Answers Topic 13 Shapes and Their Attributes 120
Rows: _____ + _____ + _____ = ______ squares
Columns: _____ + _____ + _____ + _____ + _____ = _____ squares
Answer:15
Explanation:
Each row has 5 squares by adding the rows 5+ 5+5=15
Each column has 3 squares by adding squares 3 +3+3+3+3=15.

Question 13.
Kerry wants a design that shows thirds. Which designs could Kerry use? Choose all that apply.
Envision Math Common Core Grade 2 Answers Topic 13 Shapes and Their Attributes 121
Answer:
Kerry wants a design that shows thirds are 3 and 4 rectangles are divided thirds
1,2,5 are not equally divided.

Question 14.
Is the solid figure a cube? Choose Yes or No.
Envision Math Common Core Grade 2 Answers Topic 13 Shapes and Their Attributes 122
Answer:
A symmetrical three-dimensional shape, either solid or hollow, contained by six equal square

Question 15.
Use the dot paper. Draw a cube.
Envision Math Common Core Grade 2 Answers Topic 13 Shapes and Their Attributes 123
Answer:

Question 16.
Divide the rectangle into rows and columns of squares the same size as the green square. Then count and record the number of squares.
Envision Math Common Core Grade 2 Answers Topic 13 Shapes and Their Attributes 124
________ squares
Answer:
Each row has 3 squares 3 + 3 = 6.

Topic 13 Performance Task

Happy Home Tina and her family moved into a new home. They bought different things for each room.

Question 1.
They hang pictures on the wall. Name the shape of each picture frame.
Envision Math Common Core Grade 2 Answers Topic 13 Shapes and Their Attributes 125
Answer:
1. Triangle
2. Rectangle.

Question 2.
The rug in the kitchen has 5 sides and 5 vertices. Draw the shape of the rug.
Name the shape. ___________
Answer: A pentagon is a polygon with 5 sides and 5 angles.

Question 3.
The wallpaper uses this pattern.
Envision Math Common Core Grade 2 Answers Topic 13 Shapes and Their Attributes 126
Name the shape in the pattern.
Write the number of sides, vertices, and angles in the shape.
_______ sides _______ vertices ________ angles
Answer:
5 sides, 5 vertices and 5 angles.

Question 4.
The living room has 2 end tables.
Envision Math Common Core Grade 2 Answers Topic 13 Shapes and Their Attributes 127
Circle the table that is a cube. Explain.
Answer: A symmetrical three-dimensional shape, either solid or hollow, contained by six equal squares

Question 5.
Tina has a new quilt for her bed. Her quilt has this design.
Envision Math Common Core Grade 2 Answers Topic 13 Shapes and Their Attributes 128
What share is green? ___________
What share is yellow? _________
Answer:
Green is 2 and yellow is 2.
Explanation:
The square is divided into 4 equals in that 2 are green and 2 are yellow.

Question 6.
Tina’s mother is making a quilt with smaller squares. She wants the quilt to have i 4 colors. Each color has an equal share.
Part A
Use 4 colors to make a quilt design below. Make the equal shares the same shape.
Design 1
Envision Math Common Core Grade 2 Answers Topic 13 Shapes and Their Attributes 129

Answer:
Each share has 4 small squares so, any shape with 4 small squares is an equal share
I can make shares that are the same shapes, these fourths are all squares.
In other designs I used different shapes for the shares.

Part B Use 4 colors to make a different quilt design below. Make equal shares that are not all the same shape.
Design 2
Envision Math Common Core Grade 2 Answers Topic 13 Shapes and Their Attributes 130
Answer:
Each share has 4 small squares so, any shape with 4 small squares is an equal share.
I can make shares that are the same shapes, these fourths are all squares.
In other designs, I used different shapes for the shares.

enVision Math Common Core Grade 2 Answer Key Topic 10 Add Within 1,000 Using Models and Strategies

Practice with the help of enVision Math Common Core Grade 2 Answer Key Topic 10 Add Within 1,000 Using Models and Strategies regularly and improve your accuracy in solving questions.

enVision Math Common Core 2nd Grade Answers Key Topic 10 Add Within 1,000 Using Models and Strategies

Envision Math Common Core Grade 2 Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 1
enVision STEM Project: Building Up to 1,000

Find Out Use drinking straws and pieces of tape. The total number of straws and pieces of tape cannot be more than 1,000. First, decide how many of each to use. Then share. Build the tallest buildings you can.
Journal: Make a Book Describe your building in a book. In your book, also:

  • Tell how many drinking straws and pieces of tape you used.
  • Tell how you would make a better building if you did it again.

Review What You Know

Vocabulary

Question 1.
Circle all of the hundreds digits in the numbers below.
Envision Math Common Core Grade 2 Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 2
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Key-Topic-10-Add-Within-1,000-Using-Models-and-Strategies-Vocabulary-Question-1
Explanation:
The digit place
Thousands   Hundreds   Tens  Ones
5                0       2
5       8
1              0                0       0
5 and 0 are in the hundreds place and these values are circled.

Question 2.
Write the expanded form of the number.
846
____
Answer:
800 + 40 + 6 is the expanded form of 846.
Explanation:
Given number is a three digit number
8 in Hundreds place
4 in Tens place
6 in Ones place

Question 3.
Write the word form of the number.
265
_____
Answer:
265 = Two hundred and sixty five.
Explanation:
Given number is a three digit number
2 in Hundreds place
6 in Tens place
5 in Ones place

Open Number Lines

Question 4.
Use the open number line to find the sum.
Envision Math Common Core Grade 2 Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 3
54 + 13 = ___
Answer:
54 + 13 = 67
Envision-Math-Common-Core-2nd-Grade-Answers-Key-Topic-10-Add-Within-1,000-Using-Models-and-Strategies-Open-Number-Lines-Question-4

Mental Math

Question 5.
Use mental math to find each sum.
40 + 37 = ____
6 + 77 + 4 = ___
Answer:
40 + 37 = 40 + (30 + 7) = (40 + 30) + 7 = 70 + 7 = 77.
6 + 77 + 4 = (6 + 4) + 77 = 10 + 77 = 87.
Explanation:
Mental math we break the number of one addend and then giving park of one addend to the other addend.
Here in 40 + 37
we break 37 as 30 + 7
now we add 40 + 30 =70 + 7 = 77.
This simplify the adding of numbers.
In 2nd Sum
6 + 77 + 4
we add 6 + 4 =10 and then 10 + 77 = 87.

Partial Sums

Question 6.
Use partial sums to add.
Envision Math Common Core Grade 2 Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 5.1
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Key-Topic-10-Add-Within-1,000-Using-Models-and-Strategies-Partial-Sums-Question-6
Explanation:
Using partial sum
we add the place values of the numbers separately.
Hundreds place value + Hundreds place value
Tens place value + Tens place value
Ones place value + Ones place value
Here
46 + 53 = (40+50) + (6 + 3) = 90 + 9 = 99
29 + 61 = (20 + 60) + (9 + 1) = 80 + 10 = 90.

pick a Project

PROJECT 10A
Envision Math Common Core Grade 2 Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 5.2
What are the run times of two of your favorite movies?
Project: Write Movie Reviews

PROJECT 10B
Envision Math Common Core Grade 2 Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 5.3
How many shots do basketball teams block?
Project: Make a Basketball Poster

PROJECT 10C
How many miles are between a State Capital and other cities?
Project: Draw a State Map
Envision Math Common Core Grade 2 Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 5.4

PROJECT 10D
How far can people hike in the Sierra Nevada Mountains?
Project: Create a Hiking Guide
Envision Math Common Core Grade 2 Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 5.5

Lesson 10.1 Add 10 and 100

Solve & Share

Activity

Forest Park Nursery sells trees.
Sal buys a maple tree for $125. A spruce free costs $10 more than a maple tree. An elm tree costs $100 more than a maple tree. What is the cost of a spruce tree? An elm tree?
Use dollar bills, place-value blocks, or mental math to solve. Be ready to explain how you solved the problem.
Envision Math Common Core Grade 2 Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 5.6

Visual Learning Bridge
Envision Math Common Core Grade 2 Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 5.7

Convince Me!
Use mental math to find 567 + 10 and 567 + 100. Explain your reasoning.

Guided Practice
Add. Use place-value blocks or mental math.

Question 1.
Envision Math Common Core Grade 2 Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 5.8
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Key-Topic-10-Add-Within-1,000-Using-Models-and-Strategies-Lesson-10.1-Add-10-and-100- Guided-Practice-Question-1

Question 2.
Envision Math Common Core Grade 2 Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 5.9
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Key-Topic-10-Add-Within-1,000-Using-Models-and-Strategies-Lesson-10.1-Add-10-and-100- Guided-Practice-Question-2
Explanation:
The square cube represents 100 square and hundreds place
cube stick represents 10 cubes and tens place
single cube represents 1 cube and ones place.
In the above image
(4 square cube + 1 cube stick + 2 cubes) + 1 cube stick
(400 + 10 + 2) + 10
Adding tens place
10 +10 = 20
the value of the  image = 400+20+2=422.

Question 3.
Envision Math Common Core Grade 2 Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 5.10
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Key-Topic-10-Add-Within-1,000-Using-Models-and-Strategies-Lesson-10.1-Add-10-and-100- Guided-Practice-Question-3
Explanation:
The square cube represents 100 square and hundreds place
cube stick represents 10 cubes and tens place
single cube represents 1 cube and ones place.
In the above image
(3 square cube + 2 square cube) + 1 square cube
(300 + 200) + 100
Adding hundreds place
500 + 100 = 600
the value of the  image = 500 + 100 = 600.

Question 4.
Envision Math Common Core Grade 2 Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 5.11
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Key-Topic-10-Add-Within-1,000-Using-Models-and-Strategies-Lesson-10.1-Add-10-and-100- Guided-Practice-Question-4
Explanation:
The square cube represents 100 square and hundreds place
cube stick represents 10 cubes and tens place
single cube represents 1 cube and ones place.
In the above image
(2 square cube + 5 cube stick + 3 cubes) + 1 Square cube
(200 + 50 + 3) + 100
Adding Hundreds place values
200 + 100 = 300
the value of the  image = 400+20+2=422.

Independent Practice
Add. Use place-value blocks or mental math.

Question 5.
164 + 100 =
Answer:
Using mental math
164 + 100
Dividing 164 into smaller parts
= (100 + 64 ) + 100
Now adding hundreds place values
100 + 100 = 200
200 + 64 = 264.
Sum = 264.

Question 6.
$837 + $10 = ___
Answer:
Using mental math
837 + 10
Dividing 837 into smaller parts
(800 + 30 + 7 ) + 10
Adding tens places
30 + 10 = 40
800+40+7 = 847.
Sum = $847.

Question 7.
329 + 100 = ___
Answer:
Using mental math
329 + 100
Dividing 329 into smaller parts
(300+ 20 + 9) + 100
Adding hundreds place
300+ 100 = 400
400+20+9 = 429
Sum = 429.

Question 8.
610 + 10 = ___
Answer:
Dividing 610 into its smaller values
(600 + 10 ) + 10
Adding tens places
10+10 = 20
= 600 + 20 =  620.
Sum = 620.

Question 9.
295 + 10 = ___
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Key-Topic-10-Add-Within-1,000-Using-Models-and-Strategies-Lesson-10.1-Add-10-and-100-Independent-Practice-Question-9

Question 10.
$497 + $100 = ___
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Key-Topic-10-Add-Within-1,000-Using-Models-and-Strategies-Lesson-10.1-Add-10-and-100-Independent-Practice-Question-10

Question 11.
790 + 10 = ___
Answer:
Dividing 790 into its smaller values
(700 + 90 ) + 10
Adding tens places
90+10 = 100
= 700 + 100 =  800.
Sum = 800.

Question 12.
693 + 100 = ___
Answer:
Dividing 693 into its smaller values
(600 + 90 + 3 ) + 100
Adding hundreds places
6 + 1 = 7
= 600 + 100 =  700.
= 700 + 90 + 3
= 793
Sum = 793.

Question 13.
900 + 100 = ___
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Key-Topic-10-Add-Within-1,000-Using-Models-and-Strategies-Lesson-10.1-Add-10-and-100-Independent-Practice-Question-13

Question 14.
460 + 10 = ___
Answer:
Dividing 460 into its smaller values
(400 + 60 ) + 10
Adding tens places
6 + 1 = 7
= 60 + 10 =  70.
=400 + 70
= 470
Sum = 470.

Question 15.
185 + 10 = ___
Answer:
Dividing 185 into its smaller values
(100 + 80 + 5 ) + 10
Adding Tens places
8 + 1 = 9
= 80 + 10 =  90.
=100 + 90 + 5
= 195
Sum = 195.

Question 16.
723 + 100 = ___
Answer:
Dividing 723 into its smaller values
(700 + 20 + 3 ) + 100
Adding hundreds places
7 + 1 = 8
= 700 + 100 =  800.
= 800 + 20 + 3
= 823
Sum = 823.

Algebra Find the missing numbers. Use mental math to solve.

Question 17.
572 + Envision Math Common Core Grade 2 Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 6.1 = 672
Answer:
Given
One addend 572 and
Sum 672
Both are 3-digit number
Hundred  Tens  Ones
5              7        2
6              7        2
The values in the tens place and ones place are same but the values in the hundreds place are different
Subtract the hundreds place values
6 – 5 = 1
600 – 500 = 100.
The missing addend is 100.
572 + 100 = 672.

Question 18.
285 + Envision Math Common Core Grade 2 Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 6.1 = 385
Answer:
Given
One addend 285 and
Sum 385
Both are 3-digit number
Hundred  Tens  Ones
2              8        5
3              8        5
The values in the tens place and ones place are same but the values in the hundreds place are different
Subtract the hundreds place values
3 – 2 = 1
300 – 200 = 100.
The missing addend is 100.
285 + 100 = 385.

Question 19.
709 = 699 + Envision Math Common Core Grade 2 Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 6.1
Answer:
Given
One addend 699 and
Sum 709
Both are 3-digit number
Hundred  Tens  Ones
6              9       9
7              0       9
The values in the  ones place are same but the values in the tens and hundreds place are different
Adding 1 to  the tens place values
9 + 1 = 10
Now the value in the tens place is 0 and 1 is carried to the hundreds place
1 is added to hundreds place vale
6 + 1 = 7
10 is the missing number.
699 + 10 = 709.

Question 20.
422 = 322 + Envision Math Common Core Grade 2 Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 6.1
Answer:
Given
One addend 422 and
Sum 322
Both are 3-digit number
Hundred  Tens  Ones
3             2        2           -Addend
4              2        2           – Sum
The values in the tens place and ones place are same but the values in the hundreds place are different
Subtract the hundreds place values
4 – 3 = 1
400 – 300 = 100.
The missing addend is 100.
322 + 100 = 422.

Question 21.
615 + Envision Math Common Core Grade 2 Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 6.1 = 625
Answer:
Given
One addend 699 and
Sum 709
Both are 3-digit number
Hundred  Tens  Ones
6              1       5       –   Addend
6              2       5       – Sum
The values in the  ones place and hundreds place are same but the values in the tens are different
subtracting   the tens place values
2 – 1 = 1
Now adding 1 to the addends tens place
1 + 1 = 2
10 is the missing number.
615 + 10 = 625.

Question 22.
600 = Envision Math Common Core Grade 2 Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 6.1 + 590
Answer:
Given
One addend 590 and
Sum 600
Both are 3-digit number
Hundred  Tens  Ones
5              9       0
6              0        0
The values in the  ones place are same but the values in the tens and hundreds place are different
Adding 1 to  the tens place values of addend
9 + 1 = 10
Now the value in the tens place is 0 and 1 is carried to the hundreds place
1 is added to hundreds place vale
5 + 1 = 6
10 is the missing number.
590 + 10 = 600.

Problem Solving

Solve each problem. Show your work.

Question 23.
enVision® STEM The Science Club asked 178 people about recycling. The club wants to ask a total of 188 people about recycling. How many more people will the Science Club need to ask?
___ more people
Answer:
Number of people The Science Club asked about recycling = 178 people
Total number of people The Science Club wants to ask about recycling = 188 people.
Number of more people  The Science Club need to ask = 188 – 178 = 10.
10 more people.
Th given number is 3 digit number
Hundred place   Tens place   Once place
1                      8                   8
1                      7                   8
The Hundreds place value and ones place values are same. but the tens place value is different
8 – 7 = 1
80 – 70 = 10.
10 more people.

Question 24.
Use Structure Jordan has four $100 bills, three $20 bills, one $10 bill, and seven $1 bills. What will Jordan’s total be if Jayla gives him one more $10 bill? What will his total be if she gives him one more $100 bill?
Envision Math Common Core Grade 2 Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 6.10
Answer:
Number of $100 bills Jordan has = 4
Number of $20 bills Jordan has = 3
Number of $10 bills Jordan has = 1
Number of $1 Jordan has = 7
Number of $10 bills Jayla gave to Jordan = 1
Total money Jordan have after adding Jayla’s $10 bill = $400 + $60 + $10 + $10 + $7 = $487
Jayla gave more $100 bill to Jordan
Total money Jordan have after adding 1 more $100 bill = $487 + $100 = $587.
The value of the hundreds place  = 4
adding 1
4 + 1 = 5.
The value of the hundreds place is 5. The remaining values remain same.
Total money Jordan has = $587.

Question 25.
Higher Order Thinking Think of a 3-digit number. Write a story about adding 100 to your number. Then write an equation to show your solution.
Envision Math Common Core Grade 2 Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 6.11
Answer:
A hotel has 250 rooms. Their is an event organized at the hotel the hotel is booked completely. Before the day of event there are 150 rooms filled. How many rooms need to be filled?
Number of room filled = 150
Total number of rooms in the hotel = 250
Number of more rooms to be filled = 250 – 150 = 100 rooms.
100 more rooms need to be filled.
Here the tens and ones place values are same but the Hundreds place value is different.
2 – 1 = 1
The difference in the hundreds place value is 1.
The difference is 100.

Question 26.
Assessment Practice Which equations are true? Choose all that apply.
Envision Math Common Core Grade 2 Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 6.12 $251 + $10 = $351
Envision Math Common Core Grade 2 Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 6.12 528 + 100 = 628
Envision Math Common Core Grade 2 Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 6.12 528 + 10 = 538
Envision Math Common Core Grade 2 Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 6.12 $251 + $100 = $351
Answer:
The Equations that are true are
2. 528 + 100 = 628
Adding the hundreds place values
5 + 1 = 6
Sum = 528 + 100 =  628
3. 528 + 10 = 538
Adding the tens places
2 + 1 = 3
Sum = 528 + 10 = 538.
4. $251 + $100 = $ 351
Adding the hundreds place values
2 + 1 = 3
Sum = $251 + $100 =  $351

Lesson 10.2 Add on an Open Number Line

Activity

Solve & Share

Use the open number line to find 598 + 123. Explain your work.

Envision Math Common Core 2nd Grade Answers Topic 10 Add Within 1,000 Using Models and Strategies 7.1

Visual Learning Bridge
Envision Math Common Core 2nd Grade Answers Topic 10 Add Within 1,000 Using Models and Strategies 7.2

Convince Me!
Explain how you can use an open number line to find 599 + 205.

Guided Practice
Use an open number line to find each sum.

Question 1.
375 + 118 = ___
Envision Math Common Core 2nd Grade Answers Topic 10 Add Within 1,000 Using Models and Strategies 7.3
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Key-Topic-10-Add-Within-1,000-Using-Models-and-Strategies- Lesson-10.2-Add-on-an-Open-Number-Line- Guided-Practice-Question-1
Explanation:
Here we are breaking the addend into hundreds , tens, ones which does not change its value.
The equation is 375 + 118
118 is the addend
Breaking the addend 118
118 = 100+ 10+5+3
So, adding these to 375
375+100=475
475+10 = 485
485+  5 =   490
490 + 3=  493
375 +118 = 493.

Question 2.
670 + 232 = ___
Envision Math Common Core 2nd Grade Answers Topic 10 Add Within 1,000 Using Models and Strategies 7.4
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Key-Topic-10-Add-Within-1,000-Using-Models-and-Strategies- Lesson-10.2-Add-on-an-Open-Number-Line- Guided-Practice-Question-2

Explanation:
Here we are breaking the addend into hundreds , tens, ones which does not change its value.
The equation is 670 + 232
232 is the addend
Breaking the addend 232
232 = 100+ 100 + 20 + 10 + 2
So, adding these to 670
670 +100 = 770
770 +100 = 870
870 + 20 = 890
890 + 10 = 900
900 + 2 =  902
670 + 232 = 902.

Independent Practice
Use an open number line to find each sum.

Question 3.
269 + 156 = ___
Envision Math Common Core 2nd Grade Answers Topic 10 Add Within 1,000 Using Models and Strategies 7.5
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Key-Topic-10-Add-Within-1,000-Using-Models-and-Strategies- Lesson-10.2-Add-on-an-Open-Number-Line-Independent-Practice-Question-3
Explanation:
Here we are breaking the addend into hundreds , tens, ones which does not change its value.
The equation is 269 + 156
156 is the addend
Breaking the addend 156
156 = 100 + 20 + 20 + 10 + 5 + 1
So, adding these to 269
269 + 100 = 369
369 + 20 = 389
389 + 20 = 409
409 + 10 =  419
419 + 5 = 424
424 + 1 = 425

Question 4.
637 + 242 = ___
Envision Math Common Core 2nd Grade Answers Topic 10 Add Within 1,000 Using Models and Strategies 7.6
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Key-Topic-10-Add-Within-1,000-Using-Models-and-Strategies- Lesson-10.2-Add-on-an-Open-Number-Line-Independent-Practice-Question-4

Explanation:
Here we are breaking the addend into hundreds , tens, ones which does not change its value.
The equation is 637 + 242
242 is the addend
Breaking the addend 242
242 = 100+ 100 + 20 + 20 + 2
So, adding these to 637
637 +100 = 737
737 +100 = 837
837 + 20 = 857
857 + 20 = 877
877 + 2 = 879
637 + 242 = 879.

Question 5.
886 + 114 = ___
Envision Math Common Core 2nd Grade Answers Topic 10 Add Within 1,000 Using Models and Strategies 7.7
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Key-Topic-10-Add-Within-1,000-Using-Models-and-Strategies- Lesson-10.2-Add-on-an-Open-Number-Line-Independent-Practice-Question-5

Explanation:
Here we are breaking the addend into hundreds , tens, ones which does not change its value.
The equation is 886 + 114
114 is the addend
Breaking the addend 114
114 = 100+ 10 + 4
So, adding these to 886
886 +100 = 986
986 +10 = 996
996 + 4 = 1000
886 + 114 = 1000.

Question 6.
208 + 598 =
Envision Math Common Core 2nd Grade Answers Topic 10 Add Within 1,000 Using Models and Strategies 7.8
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Key-Topic-10-Add-Within-1,000-Using-Models-and-Strategies- Lesson-10.2-Add-on-an-Open-Number-Line-Independent-Practice-Question-6

Explanation:
Here we are breaking the addend into hundreds , tens, ones which does not change its value.
The equation is 208 + 598
598 is the addend
Breaking the addend 598
598 = 100+ 100 + 100 + 100 + 100 + 50 + 40 + 5 + 3
598 = 500 + 50+ 40 + 5 + 3
So, adding these to 208
208 + 100 = 308
308 + 100 = 408
408 + 100 = 508
508 + 100 = 608
608 + 100 = 708
708 + 50 = 758
758 + 40 = 798
798 + 5 = 803
803 + 3 = 806

Question 7.
Higher Order Thinking Lisa finds 550 + 298 using the open number line below. Is her work correct? Explain.
Envision Math Common Core 2nd Grade Answers Topic 10 Add Within 1,000 Using Models and Strategies 7.9
Envision Math Common Core 2nd Grade Answers Topic 10 Add Within 1,000 Using Models and Strategies 7.10
Answer:
No, Lisa work is not correct as of addition expression.
The correct way is as below
550 + 298
breaking the addend 298 into hundreds , tens, ones
298 = 100 + 100 + 50 + 40 + 5 + 3 or
298 = 200 + 90 + 8.

Problem Solving
Use an open number line to find each sum.

Question 8.
Reasoning José has 181 cards. He collects 132 more cards. How many cards does he have now?
Envision Math Common Core 2nd Grade Answers Topic 10 Add Within 1,000 Using Models and Strategies 7.11
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Key-Topic-10-Add-Within-1,000-Using-Models-and-Strategies- Lesson-10.2-Add-on-an-Open-Number-Line-Problem-Solving-Question-8

Question 9.
Vocabulary Complete the sentence using two of these terms.
Envision Math Common Core 2nd Grade Answers Topic 10 Add Within 1,000 Using Models and Strategies 7.12>
Answer:

Question 10.
Higher Order Thinking Use open number lines to find 446 +215 in two different ways.
446 + 215 = ___
Envision Math Common Core 2nd Grade Answers Topic 10 Add Within 1,000 Using Models and Strategies 100
Answer:

Question 11.
Assessment Practice Mary uses an open number line to find 286 + 137. All of the jumps she draws are greater than 1. Draw what Mary could have done. Write the sum.
286 + 137 = ___
Envision Math Common Core 2nd Grade Answers Topic 10 Add Within 1,000 Using Models and Strategies 7.13
Answer:

Lesson 10.3 Add Using Models

Solve & Share

Activity

Use place-value blocks to find 243 + 354. Tell which place value you added first and why. Then draw a picture to show your work.
Envision Math Common Core 2nd Grade Answers Topic 10 Add Within 1,000 Using Models and Strategies 7.14

Visual Learning Bridge
Envision Math Common Core 2nd Grade Answers Topic 10 Add Within 1,000 Using Models and Strategies 7.15

Convince Me!
Are the tens regrouped in the example above? How do you know?

Guided Practice

Use place-value blocks to find each sum. Regroup if needed.

Question 1.
223 + 106 = ___
Envision Math Common Core 2nd Grade Answers Topic 10 Add Within 1,000 Using Models and Strategies 8.1
Answer:

Question 2.
149 + 362 = ___
Envision Math Common Core 2nd Grade Answers Topic 10 Add Within 1,000 Using Models and Strategies 8.2
Answer:

Independent Practice
Use and draw blocks to find each sum. Regroup if needed.

Question 3.
151 + 324 = ___
Envision Math Common Core 2nd Grade Answers Topic 10 Add Within 1,000 Using Models and Strategies 8.3
Answer:

Question 4.
250 + 298 = ___
Envision Math Common Core 2nd Grade Answers Topic 10 Add Within 1,000 Using Models and Strategies 8.4
Answer:

Question 5.
258 + 109 = ___
Envision Math Common Core 2nd Grade Answers Topic 10 Add Within 1,000 Using Models and Strategies 8.5
Answer:

Question 6.
187 + 246 = ___
Envision Math Common Core 2nd Grade Answers Topic 10 Add Within 1,000 Using Models and Strategies 8.6
Answer:

Question 7.
236 + 318 = ___
Envision Math Common Core 2nd Grade Answers Topic 10 Add Within 1,000 Using Models and Strategies 8.7
Answer:

Question 8.
432 + 365 = ___
Envision Math Common Core 2nd Grade Answers Topic 10 Add Within 1,000 Using Models and Strategies 8.8
Answer:

Question 9.
Number Sense Jamal says that the sum of 183 + 198 is less than 300. Is Jamal’s answer reasonable? Why or why not?
Envision Math Common Core 2nd Grade Answers Topic 10 Add Within 1,000 Using Models and Strategies 8.9
Answer:

Problem Solving

Solve the problems below. Show your work.

Question 10.
Reasoning 156 children in a school are girls. 148 children in that school are boys. How many children go to that school?
Envision Math Common Core 2nd Grade Answers Topic 10 Add Within 1,000 Using Models and Strategies 8.10
___ children
Answer:

Question 11.
Higher Order Thinking Write an addition problem about stickers. Use 3-digit numbers. Then solve the problem.
Envision Math Common Core 2nd Grade Answers Topic 10 Add Within 1,000 Using Models and Strategies 8.11
Answer:

Question 12.
Assessment Practice which is the sum of 129 +268?
Envision Math Common Core Grade 2 Answers Topic 10 Add Within 1,000 Using Models and Strategies 8.12
A. 292
B. 294
C. 389
D. 397
Envision Math Common Core Grade 2 Answers Topic 10 Add Within 1,000 Using Models and Strategies 8.13
Answer:

Lesson 10.4 Continue to Add Using Models and Place Value

Activity

Solve & Share

Oak School has 256 students. Pine School has 371 students. How many students do the schools have in all?
Use place-value blocks to help. Draw your blocks below and solve.

Envision Math Common Core Grade 2 Answers Topic 10 Add Within 1,000 Using Models and Strategies 8.14

Visual Learning Bridge
Envision Math Common Core Grade 2 Answers Topic 10 Add Within 1,000 Using Models and Strategies 8.15

Convince Me!
Look at the example above. Why don’t the Il tens need to be regrouped to get the final sum?

Guided Practice
Draw blocks to find the partial sums.
Record the partial sums to find the sum.

Question 1.
236 + 252 = ___
Envision Math Common Core Grade 2 Answers Topic 10 Add Within 1,000 Using Models and Strategies 9.1
Answer:

Question 2.
328 + 124 = ___
Envision Math Common Core Grade 2 Answers Topic 10 Add Within 1,000 Using Models and Strategies 9.2
Answer:

Independent Practice

Question 3.
372 + 281 = ___
Envision Math Common Core Grade 2 Answers Topic 10 Add Within 1,000 Using Models and Strategies 9.3
Answer:

Question 4.
429 + 163 = ___
Envision Math Common Core Grade 2 Answers Topic 10 Add Within 1,000 Using Models and Strategies 9.4
Answer:

Question 5.
174 + 245 =
Envision Math Common Core Grade 2 Answers Topic 10 Add Within 1,000 Using Models and Strategies 9.5
Answer:

Question 6.
Higher Order Thinking Ben said that the sum of 157 and 137 is 284. Nikki said that Ben made a mistake. Who is correct? Explain.
Envision Math Common Core Grade 2 Answers Topic 10 Add Within 1,000 Using Models and Strategies 9.6
Answer:

Problem Solving

Solve each problem below. You can use models to help.

Question 7.
Model On Friday, 354 people went to the fair. On Saturday, 551 people went to the fair.
How many people went to the fair in all?
___ people
Envision Math Common Core Grade 2 Answers Topic 10 Add Within 1,000 Using Models and Strategies 9.7
Answer:

Question 8.
Higher Order Thinking Write an addition problem in which the partial sum for tens is greater than 10 tens. Draw blocks and show partial sums to solve.
___ + ___ = ___
Envision Math Common Core Grade 2 Answers Topic 10 Add Within 1,000 Using Models and Strategies 9.8
Answer:

Question 9.
Assessment Practice Find 448 + 323. Draw place-value blocks and show partial sums to solve.
448 + 323 = ___
Envision Math Common Core Grade 2 Answers Topic 10 Add Within 1,000 Using Models and Strategies 9.9
Answer:

Lesson 10.5 Add Using Place Value and Partial Sums

Activity

Solve & Share
On Monday, 248 people visit the museum. On Tuesday, 325 people visit the museum. How many people visit the museum on Monday and Tuesday? Solve any way you choose. Be prepared to explain your thinking.
Envision Math Common Core Grade 2 Answers Topic 10 Add Within 1,000 Using Models and Strategies 10.1

Visual Learning Bridge
Envision Math Common Core Grade 2 Answers Topic 10 Add Within 1,000 Using Models and Strategies 10.2

Convince Me!
Can the problem above be solved by adding the ones first, then the tens, and then the hundreds ? Explain.

Guided Practice
Add. Use partial sums. Show your work. Use place-value blocks if needed.

Question 1.
425 + 148 = ___
Envision Math Common Core Grade 2 Answers Topic 10 Add Within 1,000 Using Models and Strategies 10.3
Answer:

Question 2.
394 + 276 = ___
Envision Math Common Core Grade 2 Answers Topic 10 Add Within 1,000 Using Models and Strategies 10.4
Answer:

Independent Practice

Add. Use partial sums. Show your work.

Question 3.
Envision Math Common Core Grade 2 Answers Topic 10 Add Within 1,000 Using Models and Strategies 10.5
Answer:

Question 4.
Envision Math Common Core Grade 2 Answers Topic 10 Add Within 1,000 Using Models and Strategies 10.6
Answer:

Question 5.
Envision Math Common Core Grade 2 Answers Topic 10 Add Within 1,000 Using Models and Strategies 10.7
Answer:

Question 6.
Envision Math Common Core Grade 2 Answers Topic 10 Add Within 1,000 Using Models and Strategies 10.8
Answer:

Question 7.
Envision Math Common Core Grade 2 Answers Topic 10 Add Within 1,000 Using Models and Strategies 10.9
Answer:

Question 8.
Higher Order Thinking Mark found the sum of 127 and 345. Explain his mistake. What is the correct sum?
Envision Math Common Core Grade 2 Answers Topic 10 Add Within 1,000 Using Models and Strategies 11.1
Answer:

Question 9.
Reasoning Rhea has a $100 bill, four $20 bills, one $10 bill, and three $5 bills. Is this amount greater or less than $210? Explain.
Answer:

Problem Solving
Solve each problem. Show your work.

Question 10.
Look for Patterns 349 people are on a boat. 255 people are on another boat. How many people are on both boats?
Envision Math Common Core Grade 2 Answers Topic 10 Add Within 1,000 Using Models and Strategies 101
___ people
Answer:

Question 11.
163 students are in first grade. 217 students are in second grade. How many students are in both grades?
___ students
Answer:

Question 12.
Higher Order Thinking Choose a number between 100 and 400. Add 384 to your number. What is the sum? Show your work. Explain the steps you took to find the sum.
Answer:

Question 13.
Assessment Practice which is the same amount as 238 + 164? Choose all that apply.
Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 12.1 200 + 190 + 12
Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 12.1 300 + 90 + 12
Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 12.1 402
Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 12.1 400 + 10 + 2
Answer:

Lesson 10.6 Explain Addition Strategies

Activity

Solve & Share

Find 375 + 235. Explain your strategy. Then explain why your strategy works.
Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 12.3

Visual Learning Bridge
Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 12.4

Convince Me!
Choose a strategy shown above. Explain why it works.

Guided Practice

Use the strategy to solve the problem. Show your work. Then explain your work.

Question 1.
624 + 248 = 872
Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 12.5
Answer:

Independent Practice

Choose any strategy to solve each addition problem. Show your work. Then explain why the strategy works.

Question 2.
212 + 487 = ___
Answer:

Question 3.
874 + 109 = ___
Answer:

Question 4.
419 + 532 = ___
Answer:

Question 5.
650 + 270 = ___
Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 12.17
Answer:

Problem Solving

Solve each problem any way you choose. Show your work.

Question 6.
Reasoning Lee School needs 407 folders for its students. Jefferson School needs 321 folders for its students. How many folders do both schools need?
___ folders
Answer:

Question 7.
Reasoning There are 229 people at the football game. 108 more people arrive at the game. How many people are at the football game now?
___ people
Answer:

Question 8.
Higher Order Thinking Tommy found 125 + 598. Since 598 is close to 600, he added 125 + 600 = 725. Then he subtracted 2 to get 723. Why did Tommy subtract 2? Explain.
Answer:

Question 9.
Assessment Practice There are 192 ants on an ant farm. 397 more ants join the ant farm. How many ants are on the ant farm now? Use the number line to solve. Explain.
Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 13.2
Answer:

Lesson 10.7 Repeated Reasoning

Problem Solving

Activity

Solve & Share

Solve these problems any way you choose. Explain patterns you see.
63 + 28 = ?
263 + 128 = ?

Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 13.3

Thinking Habits
What can I use from one problem to help with another problem? Are there things that repeat?

Visual Learning Bridge
Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 13.4

Convince Me!
If you start with 36 and add on 24, in the example above, will you get the same sum? Explain.

Guided Practice
Use repeated reasoning to solve the two problems. Circle the digits that are the same in the sums. Explain why the sums are different.

Question 1.
Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 13.5
Answer:

Independent Practice

Solve each problem.

Question 2.
Write a problem where you need to regroup to make a ten or a hundred. Each addend must be three digits. Draw place-value blocks to solve your problem. Then explain why you needed to regroup.
___ + ___ = ____
Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 14.1
Answer:

Question 3.
Write a problem where you do not need to regroup to make a ten or a hundred. Each addend must be three digits. Draw place value blocks to solve your problem. Then explain why you did not need to regroup.
___ + ___ = ____
Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 14.2
Answer:

Problem Solving

Performance Task

Tickets Sold
The table shows how many tickets were sold at a theater. How many tickets were sold on Thursday and Saturday in all?
Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 14.4

Question 4.
Make Sense Which numbers and operation can you use to solve the problem?
Answer:

Question 5.
Model Write an equation that shows the problem you need to solve.
Envision Math Common Core 8th Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 105
Answer:

Question 6.
Generalize Use what you know about adding 3-digit numbers to solve the problem. Explain what you did.
Answer:

Topic 10 Fluency Practice

Point&Tally

Find a partner. Get paper and a pencil. Each partner chooses a different color: light blue or dark blue.
Partner I and Partner 2 each point to a black number at the same time. Both partners subtract Partner 2’s number from Partner l’s number.
If the answer is on your color, you get a tally mark. Work until one partner gets seven tally marks.
Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 15.1

Topic 10 Vocabulary Review

Understand Vocabulary

Choose a term from the Word List to complete each sentence.

Word List
• addend
• break apart
• digits
• hundreds
• mental math
• open number line
• partial sum
• sum

Question 1.
When adding 193 + 564, the sum of 90 + 60 is called a ___
Answer:

Question 2.
In 709 + 187, 709 is an ___
Answer:

Question 3.
You can use an ___ to count on.
Answer:

Question 4.
In 841, there are ___ hundreds
Answer:

Question 5.
Give the value of each digit in 610.
Answer:

Question 6.
Use mental math to find 198 + 362.
Answer:

Use Vocabulary in Writing

Question 7.
Use words to tell how to find 249 + 201. Use terms from the Word List.
Answer:

Topic 10 Reteaching

Set A
You can use mental math to add 10 or 100 to 362.
Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 20.1

Add using place-value blocks or mental math.

Question 1.
600 + 10 = ___
Answer:

Question 2.
345 + 100 = ___
Answer:

Question 3.
543 + 100 = ___
Answer:

Question 4.
800 + 100 = ___
Answer:

Question 5.
799 + 10 = ___
Answer:

Question 6.
119 + 10 = ___
Answer:

Set B
You can use an open number line to add. Find 327 + 126.
First, place 327 on the line and then count on by 100s, 10s, and 1s.
Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 22.11
Use an open number line to find each sum.

Question 7.
594 + 132 = ___
Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 22.5
Answer:

Question 8.
157 + 245 = ___
Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 22.6
Answer:

Set C
You can use or draw place-value blocks and use partial sums to add. Find 276 + 137.
Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 30.1

Add. Use partial sums. Show your work. Use drawings of blocks if needed.

Question 9.
408 + 326 = ___
Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 30.2
Answer:

Set D

Thinking Habits
Repeated Reasoning
What can I use from one problem to help with another problem? Are there things that repeat?
Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 30.3

Solve each problem. Use partial sums and repeated reasoning. Use drawings of blocks if needed.

Question 10.
Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 40.1
Circle the digits that are alike in each sum.
Answer:

Topic 10 Assessment Practice

Question 1.
Emily has 100 sun stickers. She has 382 star stickers and 10 moon stickers. How many sun and star stickers does Emily have?
Answer:

Question 2.
Tyrone collects baseball cards. He gives 138 cards to his friend. Now he has 428 cards. How many cards did Tyrone have before he gave some away?
___ cards
Answer:

Question 3.
Use the open number line to solve the problem. Write the missing numbers in the boxes.
421 + 250 = ?
Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 60.1
Answer:

Question 4.
Which is the same amount as 528 + 167? Choose all that apply.
Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 60.2 500 + 80 + 15
Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 60.2 500 + 180 + 15
Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 60.2 600 + 90 + 5
Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 60.2 600 + 80 + 15
Answer:

Question 5.
Choose all the equations in which the sum is 488.
Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 60.2 478 + 10 = ?
Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 60.2 388 + 100 = ?
Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 60.2 248 + 240 = ?
Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 60.2 200 + 265 = ?
Answer:

Question 6.
Rich has 335 pennies. Beth has 58 more pennies than Rich. How many pennies do they have in all?
Hundreds
Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 60.20
A. 277
B. 393
C. 628
D. 728
Answer:

Question 7.
Use place value and partial sums to find 472 + 256. Show your work.
Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 62.1
472 + 256 = ___
Answer:

Question 8.
Molly reads 184 pages. Pat reads 294 pages. What is the total number of pages they read in all?
Use any strategy. Show your work and explain.
Envision Math Common Core 2nd Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 63.0
Answer:

Question 9.
On Saturday, 449 people visit the zoo. On Sunday, 423 people visit the zoo. How many people visit the zoo in all? Use the open number line to solve. Explain your work.
Envision Math Common Core 8th Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 63.1
Answer:

Topic 10 Performance Task

Recycling Race
Westbrook School is having a recycling contest. The table shows the number of cans each grade collected in February.
Envision Math Common Core 8th Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 63.2
Answer:

Question 1.
How many cans did the first-grade students and the second-grade students collect in all?
Use the open number line to solve.
Envision Math Common Core 8th Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 72.1
__ cans
Answer:

Question 2.
Bruce used partial sums to find how many cans the third-grade students and fourth-grade students collected in all.
Envision Math Common Core 8th Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 72.2
Do you agree with his answer?
Circle yes or no.
Explain your answer.
Envision Math Common Core 8th Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 72.3
Answer:

Question 3.
Which two grades collected a total of 689 cans? Choose any strategy to solve the problem. Show your work. Explain which strategy you used.

The ___ grade and the ___ grade collected a total of 689 cans.
Envision Math Common Core 8th Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 80.1
Answer:

Question 4.
The second-grade collected 432 cans in March. They collected 198 cans in April. Tom and Bill find how many cans the class collected in March and April.
Envision Math Common Core 8th Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 80.2
Who added correctly? Explain.
Envision Math Common Core 8th Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 80.3
Who answered incorrectly? What did he do?
Envision Math Common Core 8th Grade Answer Key Topic 10 Add Within 1,000 Using Models and Strategies 80.4
Answer:

enVision Math Common Core Grade 2 Answer Key Topic 5 Subtract Within 100 Using Strategies

Practice with the help of enVision Math Common Core Grade 2 Answer Key Topic 5 Subtract Within 100 Using Strategies regularly and improve your accuracy in solving questions.

enVision Math Common Core 2nd Grade Answers Key Topic 5 Subtract Within 100 Using Strategies

Essential Question:
What are strategies for subtracting numbers to 100?
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 1

enVision STEM Project: Heating, Cooling, and Subtraction
Find Out Have an adult help you heat and cool water and other · materials. Find out if water and ice can change back and forth. Find out if heating and cooling an egg can change it back and forth.
Journal: Make a Book Show what you learn in a book. In your book, also:

  • Tell about how heating and cooling are related
  • Tell about how addition and subtraction are related

Review What You Know

Vocabulary
Question 1.
Circle each difference in the math problems shown below.
15 – 5 = 10
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 2
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-2
Explanation:
In the above image we can observe two mathematical operations one is Subtraction and other is addition. Here we have to circle the difference in the above problems. By subtracting five from fifteen then the difference is 10. So draw a circle to the difference 10. By subtracting seven from the fourteen then the difference is 7. So draw a circle for 7. By adding 23 with 32 then the sum is 55. Here we are adding the two numbers so don’t draw a circle for 55.

Question 2.
Circle the statement if it describes mental math.
Math that is done with paper and pencil
Math that you can do in your head
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-2(1)
Explanation:
Mental math means the Math that we can do in our head. So draw a circle for Math that you can do in your head.

Question 3.
Circle the statement if it describes compatible numbers.
Numbers that are close to numbers that you want to add or subtract
Numbers that you can add or subtract using mental math
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-2(2)
Explanation:
In mathematics, compatible numbers are the numbers that are easy to add, subtract, multiply, or divide mentally. Compatible numbers are close in value to the actual numbers that make estimating the answer and computing problems easier. We can round the numbers to the nearest ten, hundred, thousand or ten thousand to make them compatible numbers. So draw a circle for Numbers that are close to numbers that you want to add or subtract. Numbers that you can add or subtract using mental math.

Addition and Subtraction Facts
Question 4.
Complete the related addition and subtraction facts below.
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 3
You can use addition facts to help you subtract.
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-3
Explanation:
In the above image we can observe two problems.
First one we have to perform addition operation. By adding six with seven then the sum is thirteen.
Second one we have to perform subtraction operation. Subtract seven from the thirteen then the difference is six.

Question 5.
Write each sum or difference.
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 4
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-4
Explanation:
In the above image we can observe two arithmetical operations. The addition is taking two or more numbers and adding them together results sum. Subtraction is an arithmetic operation that represents the operation of removing objects from a collection.
First is addition operation. Add four with seven then the sum is eleven.
Second is subtraction operation. Subtract three from twelve then the difference is nine.
Third is addition operation. Add nine with six then the sum is fifteen.
Fourth is subtraction operation. Subtract eight from sixteen then the difference is eight.

Math Story
Question 6.
Tim has 25 stamps. Roy gives him 51 more stamps. How many stamps does Tim have now?
________ stamps
Answer:
25 + 51 = ?
25 + 51 = 76
Time have 76 stamps.
Explanation:
Tim has 25 stamps. Roy gives him 51 more stamps. Add 25 stamps with 51 stamps then the sum is 76 stamps. Now Tim have 76 stamps.

Pick a Project

PROJECT 5A
How much does the largest gopher tortoise weigh?
Project: Write a Story About a Tortoise
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 5

PROJECT 5B
How does the temperature change where you live?
Project: Create a Weather Report
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 6

PROJECT 5C
How many moons do some planets in our solar system have?
Project: Research and Compare Moons
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 7

3-ACT MATH PREVIEW

Math Modeling
Laundry Day
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 8

Lesson 5.1 Subtract Tens and Ones on a Hundred Chart

Solve & Share
How can you use the hundred chart to help you find 57 – 23? Explain. Write an equation.
I can … use a hundred chart to subtract tens and ones.
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 9
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-9
Explanation:
Subtraction is an arithmetic operation that represents the operation of removing objects from a collection. Start at 57 then count back two tens and 3 ones then we land on 34. The difference is 34.

Visual Learning Bridge
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 10

Convince Me! How can you use a hundred chart to find 60 – 18?
Subtraction is an arithmetic operation that represents the operation of removing objects from a collection.
Start at 60 and go up 1 row to 50 and to the left 8 spaces to the 42. The difference is 42.
Explanation:
18 comprises of 1 ten and 8 ones. So, we need to start at 60 and count back 1 ten and 8 ones.
After counting back 1 ten we will land at 50 from 60. Now we have to count back 8 ones from 50. Finally, we land on 42 which is the subtraction value.

Guided Practice

Subtract using the hundred chart. Draw arrows if you need to.
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 11
Question 1.
69 – 36 = ________
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-11
69 – 36 = 33
Explanation:
36 comprises of 3 tens and 6 ones. So, we need to start at 69 and count back 3 tens and 6 ones.
In the above image we can see that after counting back 3 tens we will land at 39 from 69. Now we have to count back 6 ones from 39. Finally, we land on 33 which is the subtraction value.

Question 2.
54 – 24 =________
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-11(1)
54 – 24 = 30
Explanation:
24 comprises of 2 tens and 4 ones. So, we need to start at 54 and count back 2 tens and 4 ones.
In the above image we can see that after counting back 2 tens we will land at 34 from 54. Now we have to count back 4 ones from 34. Finally, we land on 30 which is the subtraction value.

Question 3.
________ = 65 – 34
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-11(2)
31 = 65 – 34
Explanation:
34 comprises of 3 tens and 4 ones. So, we need to start at 65 and count back 3 tens and 4 ones.
In the above image we can see that after counting back 3 tens we will land at 35 from 65. Now we have to count back 4 ones from 31. Finally, we land on 31 which is the subtraction value.

Question 4.
47 – 22 = ________
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-11(3)
47 – 22 = 25
Explanation:
22 comprises of 2 tens and 2 ones. So, we need to start at 47 and count back 2 tens and 2 ones.
In the above image we can see that after counting back 2 tens we will land at 27 from 47. Now we have to count back 2 ones from 27. Finally, we land on 25 which is the subtraction value.

Independent Practice

Subtract using the hundred chart. Draw arrows if you need to.
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 12
Question 5.
54 – 7 = ________
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-12
54 – 7 = 47
Explanation:
07 comprises of 0 tens and 7 ones. So, we need to start at 54 and count back 0 tens and 7 ones.
In the above image we can see that after counting back 0 tens we will land at 54 from 54. Now we have to count back 7 ones from 54. Finally, we land on 47 which is the subtraction value.

Question 6.
________ = 96 – 63
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-12 (1)
33 = 96 – 63
Explanation:
63 comprises of 6 tens and 3 ones. So, we need to start at 96 and count back 6 tens and 3 ones.
In the above image we can see that after counting back 6 tens we will land at 36 from 96. Now we have to count back 3 ones from 36. Finally, we land on 33 which is the subtraction value.

Question 7.
45 – 22 = ________
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-12 (2)
45 – 22 = 23
Explanation:
22 comprises of 2 tens and 2 ones. So, we need to start at 45 and count back 2 tens and 2 ones.
In the above image we can see that after counting back 2 tens we will land at 25 from 45. Now we have to count back 2 ones from 25. Finally, we land on 23 which is the subtraction value.

Question 8.
82 – 61 = ________
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-12 (3)
82 – 61 = 21
Explanation:
61 comprises of 6 tens and 1 ones. So, we need to start at 82 and count back 6 tens and 1 ones.
In the above image we can see that after counting back 6 tens we will land at 22 from 82. Now we have to count back 1 ones from 22. Finally, we land on 21 which is the subtraction value.

Question 9.
65 – 21 = ________
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-12 (4)
65 – 21 = 44
Explanation:
21 comprises of 2 tens and 1 ones. So, we need to start at 65 and count back 2 tens and 1 ones.
In the above image we can see that after counting back 2 tens we will land at 45 from 65. Now we have to count back 1 ones from 45. Finally, we land on 44 which is the subtraction value.

Question 10.
________ = 79 – 47
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-12 (5)
32 = 79 – 47
Explanation:
47 comprises of 4 tens and 7 ones. So, we need to start at 79 and count back 4 tens and 7 ones.
In the above image we can see that after counting back 4 tens we will land at 39 from 79. Now we have to count back 7 ones from 39. Finally, we land on 32 which is the subtraction value.

Question 11.
84 – 6 = ________
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-12 (6)
84 – 6 = 78
Explanation:
06 comprises of 0 tens and 6 ones. So, we need to start at 84 and count back 0 tens and 6 ones.
In the above image we can see that after counting back 0 tens we will land at 84 from 84. Now we have to count back 6 ones from 84. Finally, we land on 78 which is the subtraction value.

Algebra Write the digit that makes each equation true.
Question 12.
73 – ☐2 = 41
5☐ – 32 = 26
Answer:
73 – 32 = 41
58 – 32 = 26
Explanation:
In the first equation the digit that make the equation true is 3. Subtract tens part. Subtract three from seven then the difference is 4. Subtract ones. Subtract two from three then the difference is 1. The equation is 73 – 32 = 41.
In the second equation the digit that makes the equation true is 8. Subtract tens part. Subtract three from five then the difference is 2. Subtract ones. Subtract two from eight then the difference is 6. The equation is 58 – 32 = 26.

Question 13.
46 – ☐1 = 15
78 – 36 = ☐2
Answer:
46 – 31 = 15
78 – 36 = 42
Explanation:
In the first equation the digit that make the equation true is 3. Subtract tens part. Subtract three from four then the difference is 1. Subtract ones. Subtract one from six then the difference is 5. The equation is 46 – 31 = 15.
In the second equation the digit that makes the equation true is 4. Subtract tens part. Subtract three from seven then the difference is 4. Subtract ones. Subtract six from eight then the difference is 2. The equation is 78 – 36 = 42.

Question 14.
53 – ☐2 = 31
99 – ☐3 = 16
Answer:
53 – 22 = 31
99 – 83 = 16
Explanation:
In the first equation the digit that make the equation true is 2. Subtract tens part. Subtract two from five then the difference is 3. Subtract ones. Subtract two from three then the difference is 1. The equation is 53 – 22 = 31.
In the second equation the digit that makes the equation true is 8. Subtract tens part. Subtract eight from nine then the difference is 1. Subtract ones. Subtract three from nine then the difference is 6. The equation is 99 – 83 = 16.

Problem Solving

Use Tools Use the hundred chart to solve the problems below.
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 13
Question 15.
Darren’s puzzle has 98 pieces. Darren fits 55 pieces together. How many more pieces does Darren still need to fit to complete the puzzle?
________ Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 14 ______ = ________ pieces

Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-13
Darren still need to fit 43 more pieces to complete the puzzle.
Explanation :
Darren’s puzzle has 98 pieces. Darren fits 55 pieces together. So subtract 55 pieces from 98 pieces.
55 comprises of 5 tens and 5 ones. So, we need to start at 98 and count back 5 tens and 5 ones.
In the above image we can see that after counting back 5 tens we will land at 48 from 98. Now we have to count back 5 ones from 48. Finally, we land on 43 which is the subtraction value. Darren still need to fit 43 more pieces to complete the puzzle.

Question 16.
A test has 86 questions. Glenda needs to answer 23 more questions to finish the test. How many test questions has Glenda answered already?
______ questions
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-13 (1)
86 – 23 = 63
Glenda answered 63 questions already.
Explanation:
A test has 86 questions. Glenda needs to answer 23 more questions to finish the test. So subtract 23 questions from 83 questions.
23 comprises of 2 tens and 3 ones. So, we need to start at 86 and count back 2 tens and 3 ones.
In the above image we can see that after counting back 2 tens we will land at 66 from 86. Now we have to count back 3 ones from 66. Finally, we land on 63 which is the subtraction value. Glenda answered 63 questions already.

Question 17.
Higher Order Thinking Chris wants to subtract 76 – 42. Write the steps he can take to subtract 42 from 76 on the hundred chart.
Answer:
Start at 76 move up 7 times and move to the left 2 times. Then the difference is 34.
76 – 42 = 34
Explanation:
42 comprises of 4 tens and 2 ones. So, we need to start at 76 and count back 4 tens and 2 ones.
After counting back 4 tens we will land at 36 from 76. Now we have to count back 2 ones from 36. Finally, we land on 34 which is the subtraction value.

Question 18.
Assessment Practice which has a difference of 26? Choose all that apply.
☐ 56 – 30
☐ 69 – 43
☐ 75 – 49
☐ 92 – 76
Answer:
56 – 30 = 26
69 – 43 = 26
75 – 49 = 26
92 – 76 = 16
First 3 equations have the difference of 26.
Explanation:
Subtract 30 from 56 then the difference is 26.
Subtract 43 from 69 then the difference is 26.
Subtract 49 from 75 then the difference is 26.
Subtract 76 from 92 then the difference is 16.

Lesson 5.2 Count Back to Subtract on an Open Number Line

Solve & Share
Jeremy had 56 bug stickers. He gave 24 stickers to Eric. How many bug stickers does Jeremy have left? Use the open number line below to show your work.
I can … use an open number line to subtract tens and ones.
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 15
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-15
Jeremy have 32 bug stickers left.
Explanation:
Jeremy had 56 bug stickers. He gave 24 stickers to Eric. Here we used an open number line. First place 56 on the line. Here subtracting number 24 is 2 tens and 4 ones. So, count back 2 tens from 56. The numbers are 46, 36. Then count back 4 ones from 36. The numbers are 35, 34, 33, 32. Subtract 24 stickers from 56 stickers then the difference is 32.Jeremy have 32 bug stickers.

Visual Learning Bridge
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 16

Convince Me! How can the open number line help you keep track as you count back?
I am able to see my progress.

Guided Practice

Use an open number line to find each difference.
Question 1.
28 – 24 = ___________
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 17
Answer:
28 – 24 = 4
Explanation:
In the above image we used a open number line to find the difference. First place 28 on the line. The subtracting number 24 is 2 tens and 4 ones. So, count back 2 tens from 28. The numbers are 18, 8. Then count back 4 ones from 8. The number is 4. By subtracting 24 from 28 the difference is 4.

Question 2.
50 – 35 = ___________
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 18
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-18
50 – 35 = 15
Explanation:
In the above image we used a open number line to find the difference. First place 50 on the line. The subtracting number 35 is 3 tens and 5ones. So, count back 3 tens from 50. The numbers are 40, 30, 20. Then count back 5 ones from 20. The number is 5. By subtracting 35 from 50 the difference is 15.

Independent Practice

Use an open number line to find each difference.
Question 3.
45 – 13 = ___________
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 18
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-18 (1)
45 – 13 = 32
Explanation:
In the above image we used a open number line to find the difference. First place 45 on the line. The subtracting number 13 is 1 ten and 3 ones. So, count back 1 ten from 45. The number is 35. Then count back 3 ones from 35. The number is 32. By subtracting 13 from 45 the difference is 32.

Question 4.
63 – 22 = ___________
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 18
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-18 (2)
63 – 22 = 41
Explanation:
In the above image we used a open number line to find the difference. First place 63 on the line. The subtracting number 22 is 2 tens and 2 ones. So, count back 2 tens from 63. The numbers are 53,43. Then count back 2 ones from 43. The number is 41. By subtracting 22 from 63 the difference is 41.

Question 5.
78 – 46 = ___________
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 18
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-18 (3)
78 – 46 = 32
Explanation:
In the above image we used a open number line to find the difference. First place 78 on the line. The subtracting number 46 is 4 tens and 6 ones. So, count back 4 tens from 78. The numbers are 68, 58, 48, 38. Then count back 6 ones from 38. The number is 32. By subtracting 46 from 78 the difference is 32.

Question 6.
92 – 37 = ___________
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 18
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-18 (4)
92 – 37 = 55
Explanation:
In the above image we used a open number line to find the difference. First place 92 on the line. The subtracting number 37 is 3 tens and 7 ones. So, count back 3 tens from 92. The numbers are 82, 72, 62. Then count back 7 ones from 62. The number is 55. By subtracting 37 from 92 the difference is 55.

Question 7.
80 – 44 = ?
Break apart the number you are subtracting into tens and ones.
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 18
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-18 (5)
80 – 44 = 36 
44 is 4 tens and 4 ones.
Explanation:
In the above image we used a open number line to find the difference. First place 80 on the line. The subtracting number 44 is 4 tens and 4 ones. So, count back 4 tens from 80. The numbers are 70, 60, 50, 40. Then count back 4 ones from 40. The number is 36. By subtracting 44 from 80 the difference is 36.

Question 8.
Number Sense How many tens and ones will you count back to solve this problem: 56 – 38 = ? Solve the problem.
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 18
___________ tens ___________ ones
_______ – _______ = ________
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-18 (6)
3 tens and 8 ones
56 – 38 = 18
Explanation:
In the above image we used a open number line to find the difference. First place 56 on the line. The subtracting number 38 is 3 tens and 8 ones. So, count back 3 tens from 56. The numbers are 46, 36, 26. Then count back 8 ones from 26. The number is 18. By subtracting 38 from 56 the difference is 18.

Problem Solving

Use an open number line to solve each problem.
Question 9.
Use Tools There are 47 raffle tickets to sell for the fair. Ms. Brown’s class sells 23 raffle tickets. How many raffle tickets are left to sell?
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 18
________ raffle tickets
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-18 (7)
24 raffle tickets are left to sell.
Explanation:
There are 47 raffle tickets to sell for the fair. Ms. Brown’s class sells 23 raffle tickets. Here the subtracting number is 23. In the above image we used a open number line to find the difference. First place 47 on the line. The subtracting number 23 is 2 tens and 3 ones. So, count back 2 tens from 47. The numbers are 37, 27. Then count back 3 ones from 27. The number is 24. By subtracting 23 from 47 the difference is 24. There are 24 raffle tickets left to sell.

Question 10.
Use Tools Ethan counts 78 carrots. He sells 35 carrots at the farmers market. How many carrots does Ethan have left?
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 18
_________ carrots
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-18 (8)
Ethan have 43 carrots left.
Explanation:
Ethan counts 78 carrots. He sells 35 carrots at the farmers market. Here the subtracting number is 35. In the above image we used a open number line to find the difference. First place 78 on the line. The subtracting number 35 is 3 tens and 5 ones. So, count back 3 tens from 78. The numbers are 68, 58, 48. Then count back 5 ones from 48. The number is 43. By subtracting 35 carrots from 78 carrots the difference is 43 carrots. Ethan have 43 carrots left.

Question 11.
Higher Order Thinking Show two different ways to find 63 – 25 using the open number lines.
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 18
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 18
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-18 (9)

Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-18 (10)

63 – 25 = 38
Explanation:
In the above image we used a open number lines to find the difference.
The first open number line.
First place 63 on the line. The subtracting number 25 is 2 tens and 5 ones. So, count back 2 tens from 63. The numbers are 53,43. Then count back 5 ones from 43. The number is 38. By subtracting 25 from 63 the difference is 38.
The second open number line.
First place 63 on the line. The subtracting number 25 is 2 tens and 5 ones. So, count back 2 tens from 63. The number is 43. Then count back 3 ones from 43. The number is 40. After that count back 2 ones from 40. The number is 38. By subtracting 25 from 63 the difference is 38.

Question 12.
Assessment Practice Jen solved a subtraction problem using the open number line shown. Write the equation that her work below shows.
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 19
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-19
Explanation:
In the above image we can observe a open number line to find the difference. First place 56 on the line. The subtracting number 22 is 2 tens and 2 ones. So, count back 2 tens from 56. The numbers are 46, 36. Then count back 2 ones from 36. The number is 24. By subtracting 22 from 56 the difference is 34. The equation for the above open number line is 56 – 22 = 34.

Lesson 5.3 Add Up to Subtract Using an Open Number Line

Solve & Share
There are 50 children at the park. 28 are boys and the rest are girls. How many girls are at the park? Use the open number line to solve. Show your work.
I can … add up to subtract using an open number line.
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 20
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-20
There are 22 girls at the park.
Explanation:
There are 50 children at the park. 28 are boys and the rest are girls. In the above image we used a open number line to find the difference. First place 50 on the line. The subtracting number 28 is 2 tens and 8 ones. So, count back 2 tens from 50. The numbers are 40, 30. Then count back 5 ones from 30. The number is 25. Again count back 3 ones from 25. The number is 22. By subtracting 28 from 50 the difference is 22. There are 22 girls at the park.
The equation for the above open number line is 50 – 28 = 22.

Visual Learning Bridge
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 21

Convince Me! How can you add up to find 42 – 17?
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-18 (11)
42 – 17 = 25
Explanation:
In the above image we used a open number line. We can add up from 17 to subtract. First place 17 on the number line. Add 3 to get to 20. Then add 10, and 10 again to get to 40. Then add 2 to land on 42. Add the tens and ones. By adding 3,10, 10, and 2 the sum is 25. Subtracting 17 from 42 the difference is 25. We can check by adding 17 with 25 then the sum is 42.

Guided Practice

Add up to find each difference. Use an open number line.
Question 1.
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 22
Answer:
45 – 27 = 18
3 + 10 + 5 = 18
Explanation:
In the above image we used a open number line. We can add up from 27 to subtract. First place 27 on the number line. Add 3 to get to 30. Then add 10 to get to 40. Then add 5 to land on 45. Add the tens and ones. By adding 3,10, and 5 the sum is 18. Subtracting 27 from 45 the difference is 18. We can check by adding 27 with 18 then the sum is 45.

Question 2.
66 – 39 = ________
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 18
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-18 (12)
66 – 39 = 27
Explanation:
In the above image we used a open number line. We can add up from 39 to subtract. First place 39 on the number line. Add 1 to get to 40. Then add 10, and 10 again to get to 60. Then add 6 to land on 66. Add the tens and ones. By adding 1,10, 10, and 6 the sum is 27. Subtracting 39 from 66 the difference is 27. We can check by adding 39 with 27 then the sum is 66.

Independent Practice

Add up to find each difference. Use an open number line.
Question 3.
41 – 19 = ________
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 18
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-18 (13)
41 – 19 = 22
Explanation:
In the above image we used a open number line. We can add up from 19 to subtract. First place 19 on the number line. Add 1 to get to 20. Then add 10, and 10 again to get to 40. Then add 1 to land on 41. Add the tens and ones. By adding 1,10, 10, and 1 the sum is 22. Subtracting 19 from 41 the difference is 22. We can check by adding 19 with 22 then the sum is 41.

Question 4.
63 – 34 = ________
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 18
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-18 (14)
63 – 34 = 29
Explanation:
In the above image we used a open number line. We can add up from 34 to subtract. First place 34 on the number line. Add 6 to get to 40. Then add 10, and 10 again to get to 60. Then add 3 to land on 63. Add the tens and ones. By adding 6,10, 10, and 3 the sum is 29. Subtracting 34 from 63 the difference is 29. We can check by adding 34 with 29 then the sum is 63.

Question 5.
83 – 58 = ________
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 18
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-18 (15)
83 – 58 = 25
Explanation:
In the above image we used a open number line. We can add up from 58 to subtract. First place 58 on the number line. Add 2 to get to 60. Then add 10, and 10 again to get to 80. Then add 3 to land on 83. Add the tens and ones. By adding 2,10, 10, and 3 the sum is 25. Subtracting 58 from 83 the difference is 25. We can check by adding 58 with 25 then the sum is 83.

Question 6.
74 – 46 = ________
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 18
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-18 (16)
74 – 46 = 28
Explanation:
In the above image we used a open number line. We can add up from 46 to subtract. First place 46 on the number line. Add 4 to get to 50. Then add 10, and 10 again to get to 70. Then add 4 to land on 74. Add the tens and ones. By adding 4,10, 10, and 4 the sum is 28. Subtracting 46 from 74 the difference is 28. We can check by adding 46 with 28 then the sum is 74.

Question 7.
72 – 34 =________
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 18
Don’t forget to find the sum of the tens and the ones you added up. That is the difference.
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-18 (17)
72 – 34 = 38
Explanation:
In the above image we used a open number line. We can add up from 34 to subtract. First place 34 on the number line. Add 6 to get to 40. Then add 10, 10 and 10 again to get to 70. Then add 2 to land on 72. Add the tens and ones. By adding 6,10, 10, 10 and 2 the sum is 38. Subtracting 34 from 72 the difference is 38. We can check by adding 34 with 38 then the sum is 72.

Question 8.
enVision® STEM Rob had 34 snowballs. Some melted and now he has 18 snowballs. How many snowballs melted?
Envision Math Common Core 2nd Grade Answers Topic 5 Subtract Within 100 Using Strategies 23
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-23
16 snowballs melted.
Explanation:
Rob had 34 snowballs. Some melted and now he has 18 snowballs. In the above image we used a open number line. We can add up from 18 to subtract. First place 18 on the number line. Add 2 to get to 20. Then add 10 to get to 30. Then add 4 to land on 34. Add the tens and ones. By adding 2,10 and 4 the sum is 16. Subtracting 18 from 34 the difference is 16. We can check by adding 18 with 16 then the sum is 34. Total 16 snowballs melted.

Problem Solving

Add up to solve each problem. Use an open number line. Write the equations.
Question 9.
Be Precise Dino has 41 crayons. He gives 23 crayons to Bridget, and 7 crayons to Dan. How many crayons does Dino have left? Solve using two steps.
Envision Math Common Core 2nd Grade Answers Topic 5 Subtract Within 100 Using Strategies 24
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-24
Dino left with 11 crayons.
Explanation:
Dino has 41 crayons. He gives 23 crayons to Bridget, and 7 crayons to Dan.
Step 1:
In the above image we used a open number line. We can add up from 23 to subtract. First place 23 on the number line. Add 7 to get to 30. Then add 10 to get to 40. Then add 1 to land on 41. Add the tens and ones. By adding 7,10 and 1 the sum is 18. Subtracting 23 from 41 the difference is 18. Dino left with 18 crayons.
Step 2:
In the above image we used a open number line. We can add up from 7 to subtract. First place 7 on the number line. Add 3 to get to 10. Then add 8 to land on 18. Add the tens and ones. By adding 3, and 8 the sum is 11. Subtracting 7 from 18 the difference is 11. Now Dino left with 11 crayons.

Question 10.
Higher Order Thinking Show two different ways to add up to find 72 – 35.
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 18
Envision Math Common Core 2nd Grade Answer Key Topic 5 Subtract Within 100 Using Strategies 18
1. ______ – _______ = _______
Answer:
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-18 (18)
72 – 35 = 37
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-18 (19)
72 – 35 = 37
Explanation:
Step 1:
In the above image we used a open number line. We can add up from 35 to subtract. First place 35 on the number line. Add 5 to get to 40. Then add 10, 10, and 10 to get to 70. Then add 2 to land on 72. Add the tens and ones. By adding 5,10,10, 10 and 2 the sum is 37. Subtracting 35 from 72 the difference is 37. We can check by adding 35 with 37 then the sum is 72.
Step 2:
In the above image we used a open number line. We can add up from 35 to subtract. First place 35 on the number line. Add 5 to get to 40. Then add 30 to get to 70. Then add 2 to land on 72. Add the tens and ones. By adding 5, 30 and 2 the sum is 37. Subtracting 35 from 72 the difference is 37. We can check by adding 35 with 37 then the sum is 72.

Question 11.
Assessment Practice Find 46 – 25. Show your work on the open number line and then write an equation.
Envision Math Common Core 2nd Grade Answers Topic 5 Subtract Within 100 Using Strategies 25
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-25
Explanation:
In the above image we used a open number line. We can add up from 25 to subtract. First place 25 on the number line. Add 5 to get to 30. Then add 10 to get to 40. Then add 6 to land on 46. Add the tens and ones. By adding 5,10 and 6 the sum is 21. Subtracting 25 from 46 the difference is 21. We can check by adding 25 with 21 then the sum is 46.

Lesson 5.4 Break Apart Numbers to Subtract

Solve & Share
Use any strategy to find 42 – 7. Use pictures, words, or numbers to explain.
I can … break apart I-digit numbers to help me subtract mentally.
Envision Math Common Core 2nd Grade Answers Topic 5 Subtract Within 100 Using Strategies 26
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-26
Explanation:
In the above image we can observe 42 – 7 equation. There are 4 tens and 2 ones in 42. So break apart the number that we are subtracting 7 into 2 + 5. First subtract 2 from 42 then the difference is 40. Then subtract 5 from the difference 40 then the result is 35. By subtracting 7 from 42 the difference is 35.

Visual Learning Bridge
Envision Math Common Core 2nd Grade Answers Topic 5 Subtract Within 100 Using Strategies 27

Convince Me! Look at the problem above. Why wasn’t the 6 broken apart into 1 + 5 to find 33 – 6?
Answer:
Here we doesn’t use the 6 broken apart into 1 + 5 to find 33 – 6. Because we want the ones digit of “3” from the first number to match our break apart number.

Guided Practice

Subtract. Break apart the number you are subtracting. Show your work.
Envision Math Common Core 2nd Grade Answers Topic 5 Subtract Within 100 Using Strategies 28

Question 1.
Envision Math Common Core 2nd Grade Answers Topic 5 Subtract Within 100 Using Strategies 29
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-29
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-28
43 – 3 = 40
40 – 6 = 34
Explanation:
In the above image we can observe the subtracting number 9. Break apart 9 into 3 and 6. Start at 43 draw a circle for 40. First subtract 3 from 43 then the difference is 40. Draw a circle to 40. Then subtract 6 from the difference 40 then the result is 34. By subtracting 9 from 43 the difference is 34.

Question 2.
Envision Math Common Core 2nd Grade Answers Topic 5 Subtract Within 100 Using Strategies 30
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-30
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-28 (1)
24 – 4 = 20
20 – 2 = 18
Explanation:
In the above image we can observe the subtracting number 6. Break apart 6 into 4 and 2. Start at 24 draw a circle for 24. First subtract 4 from 24 then the difference is 20. Draw a circle to 20. Then subtract 2 from the difference 20 then the result is 18. By subtracting 6 from 24 the difference is 18.

Independent Practice

Subtract. Break apart the number you are subtracting. Show your work. Use a hundred chart if needed.
Question 3.
Envision Math Common Core 2nd Grade Answers Topic 5 Subtract Within 100 Using Strategies 31
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-31
35 – 5 = 30
30 – 3 = 27
Explanation:
In the above image we can observe the subtracting number 8. Break apart 8 into 5 and 3. First subtract 5 from 35 then the difference is 30. Then subtract 3 from the difference 30 then the result is 27. By subtracting 8 from 35 the difference is 27.

Question 4.
Envision Math Common Core 2nd Grade Answers Topic 5 Subtract Within 100 Using Strategies 32
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-32
41 – 1 = 40
40 – 4 = 36
Explanation:
In the above image we can observe the subtracting number 5. Break apart 5 into 1 and 4. First subtract 1 from 41 then the difference is 40. Then subtract 4 from the difference 40 then the result is 36. By subtracting 5 from 41 the difference is 36.

Question 5.
Envision Math Common Core 2nd Grade Answers Topic 5 Subtract Within 100 Using Strategies 33
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-33
82 – 2 = 80
80 – 5 = 75
Explanation:
In the above image we can observe the subtracting number 7. Break apart 7 into 2 and 5. First subtract 2 from 82 then the difference is 80. Then subtract 5 from the difference 80 then the result is 75. By subtracting 7 from 82 the difference is 75.

Question 6.
Envision Math Common Core 2nd Grade Answers Topic 5 Subtract Within 100 Using Strategies 34
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-34
53 – 3 = 50
50 – 4 = 46
Explanation:
In the above image we can observe the subtracting number 7. Break apart 7 into 3 and 4. First subtract 3 from 53 then the difference is 50. Then subtract 4 from the difference 50 then the result is 46. By subtracting 7 from 53 the difference is 46.

Question 7.
Envision Math Common Core 2nd Grade Answers Topic 5 Subtract Within 100 Using Strategies 35
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-35
97 – 7 = 90
90 – 1 = 89
Explanation:
In the above image we can observe the subtracting number 8. Break apart 8 into 7 and 1. First subtract 7 from 97 then the difference is 90. Then subtract 1 from the difference 90 then the result is 89. By subtracting 8 from 97 the difference is 89.

Question 8.
Envision Math Common Core 2nd Grade Answers Topic 5 Subtract Within 100 Using Strategies 36
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-36
64 – 4 = 60
60 – 5 = 55
Explanation:
In the above image we can observe the subtracting number 9. Break apart 9 into 4 and 5. First subtract 4 from 64 then the difference is 60. Then subtract 5 from the difference 60 then the result is 55. By subtracting 9 from 64 the difference is 55.

Question 9.
86 – 8 = _______
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-36(1)
86 – 6 = 80
80 – 2 = 78
Explanation:
In the above image we can observe the subtracting number 8. Break apart 8 into 6 and 2. First subtract 6 from 86 then the difference is 80. Then subtract 2 from the difference 80 then the result is 78. By subtracting 8 from 86 the difference is 78.

Question 10.
________ = 32 – 9
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-36(2)
32 – 2 = 30
30 – 7 = 23
Explanation:
In the above image we can observe the subtracting number 9. Break apart 9 into 2 and 7. First subtract 2 from 32 then the difference is 30. Then subtract 7 from the difference 30 then the result is 23. By subtracting 9 from 32 the difference is 23.

Question 11.
93 – 6 = _______
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-36(3)
93 – 3 = 90
90 – 3 = 87
Explanation:
In the above image we can observe the subtracting number 6. Break apart 6 into 3 and 3. First subtract 3 from 93 then the difference is 90. Then subtract 3 from the difference 90 then the result is 87. By subtracting 6 from 93 the difference is 87.

Question 12.
Algebra One number makes both equations true.
Find the missing number.
Envision Math Common Core 2nd Grade Answers Topic 5 Subtract Within 100 Using Strategies 37
The missing number is ________
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-37
The missing number is 8.
Explanation:
In the above image we can observe two mathematical operations with two missing numbers. Add 48 with 8 then the sum is 56. Next subtract 8 from 56 then the difference is 48. The number that makes the both equation true is 8.

Problem Solving

Solve each problem. Show your work.
Question 13.
Explain Karen has 7 pencils. Karen’s teacher has 45 pencils. How many fewer pencils does Karen have than her teacher? Explain how you solved the problem.

Envision Math Common Core 2nd Grade Answers Topic 5 Subtract Within 100 Using Strategies 38
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-38
45 – 5 = 40
40 – 2 = 38
Karen have 38 fewer pencils than her teacher.
Explanation:
Karen has 7 pencils. Karen’s teacher has 45 pencils. In the above image we can observe the subtracting number 7. Break apart 7 into 5 and 2. First subtract 5 from 45 then the difference is 40. Then subtract 2 from the difference 40 then the result is 38. By subtracting 7 from 45 the difference is 38. Karen have 38 fewer pencils than her teacher.

Question 14.
Higher Order Thinking Write a story problem about 63 – 8. Then solve.
63 – 8 = ________
Answer:
There are 63 stickers. I gave away 8 stickers. How many stickers are left ?
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-37(1)
63 – 3 = 60
60 – 5 = 55
55 stickers are left.
Explanation:
There are 63 stickers. I gave away 8 stickers. In the above image we can observe the subtracting number 8. Break apart 8 into 3 and 5. First subtract 3 from 63 then the difference is 60. Then subtract 5 from the difference 60 then the result is 55. By subtracting 8 from 63 the difference is 55. 55 stickers are left.

Question 15.
Duane has 24 seashells. He gives 9 shells to his cousin Rob. How many seashells does Duane have now?
Envision Math Common Core 2nd Grade Answers Topic 5 Subtract Within 100 Using Strategies 39
A. 16
B. 15
C. 14
D. 13
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-39
Option B is correct.
Explanation:
In the above image we can observe the subtracting number 9. Break apart 9 into 4 and 5. First subtract 4 from 24 then the difference is 20. Then subtract 5 from the difference 20 then the result is 15. By subtracting 9 from 24 the difference is 15. So option B is correct.
Question 16.
Assessment Practice Find 86 – 7. Show your work.
86 – 7 = __________
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-39(1)
86 – 6 = 80
80 – 1 = 79
Explanation:
In the above image we can observe the subtracting number 7. Break apart 7 into 6 and 1. First subtract 6 from 86 then the difference is 80. Then subtract 1from the difference 80 then the result is 79. By subtracting 7 from 86 the difference is 79.

Lesson 5.5 Subtract Using Compensation

Solve & Share
Yuri wants to use mental math to find 86 – 29. Show how Yuri could find the difference. Explain how she could use mental math.
I can … make numbers that are easier to subtract, then use mental math to find the difference.
Envision Math Common Core 2nd Grade Answers Topic 5 Subtract Within 100 Using Strategies 40
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-40
Explanation:
In the above image we can observe that the subtracting number 29. Break apart 29 into 20 and 9. First Subtract 20 from 86 then the difference is 66. After that break apart 9 into 6 and 3. Subtract 6 from the difference 66 then the result is 60. Then subtract 3 from 60 the difference is 57. By subtracting 29 from 86 the difference is 57.

Visual Learning Bridge
Envision Math Common Core 2nd Grade Answers Topic 5 Subtract Within 100 Using Strategies 41

Convince Me! Marc says to find 61 – 13, it’s easier to subtract 10 instead of 13. He says if you subtract 3 from 13 to get 10, you must subtract 3 more from your answer. Do you agree? Explain.
Answer:
Yes
61 – 10 = 51
51 – 3 = 48
Explanation:
I agree with Marc. It’s easier to subtract 10 instead of 13. Marc says if we subtract 3 from 13 to get 10, We must subtract 3 more from your answer. Subtract 10 from 61 then the difference is 51. Subtract 3 from 51 then the difference is 48.

Guided Practice

Use compensation to make numbers that are easier to subtract. Then solve. Show your work.
Question 1.
Envision Math Common Core 2nd Grade Answers Topic 5 Subtract Within 100 Using Strategies 42

Question 2.
Envision Math Common Core 2nd Grade Answers Topic 5 Subtract Within 100 Using Strategies 43
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-43
Explanation:
In the above image we can observe an equation 76 – 27 = ?. Here we are using compensation method to make numbers that are easier to subtract. Change both addends by adding the same amount. Then subtract using mental math. Add 3 to the addends 76 and 27. Then the equation is 79 – 30 = ?. Subtract 30 from 79 then the difference is 49.

Question 3.
Envision Math Common Core 2nd Grade Answers Topic 5 Subtract Within 100 Using Strategies 44
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-44
Explanation:
In the above image we can observe an equation 52 – 15 = ?. Here we are using compensation method to make numbers that are easier to subtract. Add 5 to 15. Then the equation is 52 – 20 = ?. Then subtract using mental math. Subtract 20 from 52 then the difference is 32. Then add 5 to the answer 32. After adding 5 to the number 32 the sum is 37. By subtracting 15 from 52 the difference is 37.

Question 4.
Envision Math Common Core 2nd Grade Answers Topic 5 Subtract Within 100 Using Strategies 45
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-45
Explanation:
In the above image we can observe an equation 93 – 39 = ?. Here we are using compensation method to make numbers that are easier to subtract. Add 1 to 39. Then the equation is 93 – 40 = ?. Then subtract using mental math. Subtract 40 from 93 then the difference is 53. Then add 1 to the answer 53. After adding 1 to the number 53 the sum is 54. By subtracting 39 from 93 the difference is 54.

Independent Practice

Use compensation to make numbers that are easier to subtract. Then solve. Show your work.
Question 5.
73 – 9 = ________
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-45(1)
Explanation:
In the above image we can observe an equation 73 – 9 = ?. Here we are using compensation method to make numbers that are easier to subtract. Add 1 to 9. Then the equation is 73 – 10 = ?. Then subtract using mental math. Subtract 10 from 73 then the difference is 63. Then add 1 to the answer 63. After adding 1 to the number 63 the sum is 64. By subtracting 9 from 73 the difference is 64.

Question 6.
35 – 16 = ________
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-45(2)
Explanation:
In the above image we can observe an equation 35 – 16 = ?. Here we are using compensation method to make numbers that are easier to subtract. Add 4 to 16. Then the equation is 35 – 20 = ?. Then subtract using mental math. Subtract 20 from 35 then the difference is 15. Then add 4 to the answer 15. After adding 4 to the number 15 the sum is 19. By subtracting 16 from 35 the difference is 19.

Question 7.
43 – 28 = ________
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-45(3)
Explanation:
In the above image we can observe an equation 43 – 28 = ?. Here we are using compensation method to make numbers that are easier to subtract. Add 2 to 28. Then the equation is 43 – 30 = ?. Then subtract using mental math. Subtract 30 from 43 then the difference is 13. Then add 2 to the answer 13. After adding 2 to the number 13 the sum is 15. By subtracting 28 from 43 the difference is 15.

Question 8.
51 – 27 = ________
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-45(4)
Explanation:
In the above image we can observe an equation 51 – 27= ?. Here we are using compensation method to make numbers that are easier to subtract. Change both addends by adding the same amount. Then subtract using mental math. Add 3 to the addends 51 and 27. Then the equation is 54 – 30 = ?. Subtract 30 from 54 then the difference is 24.

Question 9.
74 – 35 = ________
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-45(5)
Explanation:
In the above image we can observe an equation 74 – 35 = ?. Here we are using compensation method to make numbers that are easier to subtract. Change both addends by adding the same amount. Then subtract using mental math. Add 5 to the addends 74 and 35. Then the equation is 79 – 40 = ?. Subtract 40 from 79 then the difference is 39.

Question 10.
99 – 21 = ________
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-45(6)
Explanation:
In the above image we can observe an equation 99 – 21 = ?. Here we are using compensation method to make numbers that are easier to subtract. Change both addends by subtracting the same amount. Then subtract using mental math. Subtract 1 from both numbers 99 and 21. Then the equation is 98 – 20 = ?. Subtract 20 from 98 then the difference is 78.

Question 11.
Higher Order Thinking Yoshi says that to find 91 – 32, he can subtract 2 from both numbers. Then he can subtract using mental math. He says the answer is 59. Do you agree? Explain.
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-45(7)
Explanation:
Yes I agree with Yoshi. In the above image we can observe an equation 91 – 32 = ?. Here we are using compensation method to make numbers that are easier to subtract. Change both addends by subtracting the same amount. Then subtract using mental math. Subtract 2 from both numbers 91 and 32. Then the equation is 89 – 30 = ?. Subtract 30 from 89 then the difference is 59.

Problem Solving

Solve each problem. Show your thinking.
Question 12.
Make Sense There were some buttons in a jar. Mrs. Kim puts 19 more buttons in the same jar. Now there are 45 buttons in the jar. How many buttons were in the jar to begin with?
_________ buttons
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-45(8)
There are 26 buttons in the jar to begin.
Explanation:
There were some buttons in a jar. Mrs. Kim puts 19 more buttons in the same jar. Now there are 45 buttons in the jar. In the above image we can observe an equation 45 – 19 = ?. Here we are using compensation method to make numbers that are easier to subtract. Change both addends by adding the same amount. Then subtract using mental math. Add 1 to the addends 45 and 19. Then the equation is 46 – 20 = ?. Subtract 20 from 46 then the difference is 26. There are 26 buttons in the jar to begin.

Question 13.
Romi has 42 cards. Lisa has 75 cards. How many more cards does Lisa have than Romi?
Think about more cards what you are trying to find.
__________ more cards
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-45(9)
Lisa have 33 more cards than Romi.
Explanation:
Romi has 42 cards. Lisa has 75 cards. In the above image we can observe an equation 75 – 42 = ?. Here we are using compensation method to make numbers that are easier to subtract. Change both addends by subtracting the same amount. Then subtract using mental math. Subtract 2 from both numbers 75 and 42. Then the equation is 73 – 40 = ?. Subtract 40 from 73 then the difference is 33. Lisa have 33 more cards than Romi.

Question 14.
Higher Order Thinking Greg found 72 – 24. First he subtracted 20 because he thinks it is easier. Use words and numbers to explain how Greg could have found the difference.
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-45(10)
Explanation:
In the above image we can observe a equation 72 – 24. Subtract 20 from both the numbers then the equation is 52 – 4. Break apart 4 into 2 and 2. First subtract 2 from 52 then the difference is 50. Then subtract 2 from the difference 50 the result is 48.

Question 15.
Assessment Practice Use the numbers on the cards. Write the missing numbers to solve the problem.
Envision Math Common Core 2nd Grade Answers Topic 5 Subtract Within 100 Using Strategies 46
Answer:
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-5-Subtract-Within-100-Using-Strategies-46
Explanation:
In the above image we can observe an equation 53 – 28 = ?. Here we are using compensation method to make numbers that are easier to subtract. Change both addends by adding the same amount. Then subtract using mental math. Add 2 to the addends 53 and 28. Then the equation is 55 – 30 = ?. Subtract 30 from 55 then the difference is 25. The missing number is 25.

Lesson 5.6 Practice Subtracting Using Strategies

Solve & Share
Randy got 42 craft sticks for a project. He used 19 sticks. How many sticks are left? Choose any strategy. Solve. Show and explain your work.
I can … choose a strategy to help me subtract two-digit numbers.
_______ sticks
Answer:
Envision-Math-Common-Core-Grade-2-Answers-Topic-5-Subtract-Within-100-Using-Strategies-46 (1)
23 sticks are left.
Explanation:
Randy got 42 craft sticks for a project. He used 19 sticks. In the above image we can observe an equation 42 – 19 = ?. Here we are using compensation method to make numbers that are easier to subtract. Change both addends by adding the same amount. Then subtract using mental math. Add 1 to the addends 42 and 19. Then the equation is 43 – 20 = ?. Subtract 20 from 43 then the difference is 23. 23 sticks are left.

Visual Learning Bridge
Envision Math Common Core Grade 2 Answer Key Topic 5 Subtract Within 100 Using Strategies 47

Convince Me! In Another Way above, why was 3 added to 37 and then added to 25?
Answer:
In Compensation method we have to add the number on both sides. Here we are adding 3 to 37. Subtract 40 from 65 the difference is 25. Add 3 to the difference 25 then the sum is 28.

Guided Practice

Find each difference. Use any strategy. Show your work.
Question 1.
46 – 18 = ________
Envision Math Common Core Grade 2 Answer Key Topic 5 Subtract Within 100 Using Strategies 48
2 + 10 + 10 + 6 = 28
46 – 18 = 28
Explanation:
In the above image we used a open number line. We can add up from 18 to subtract. First place 18 on the number line. Add 2 to get to 20. Then add 10, and 10 to get to 40. Then add 6 to land on 46. Add the tens and ones. By adding 2, 10, 10 and 6 the sum is 28. Subtracting 18 from 46 the difference is 28. We can check by adding 18 with 28 then the sum is 46.

Question 2.
83 – 46 = _______
Envision Math Common Core Grade 2 Answer Key Topic 5 Subtract Within 100 Using Strategies 49
Answer:
Envision-Math-Common-Core-Grade-2-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-49
Explanation:
In the above image we used a open number line. We can add up from 46 to subtract. First place 46 on the number line. Add 4 to get to 50. Then add 10, 10, and 10 to get to 80. Then add 3 to land on 83. Add the tens and ones. By adding 4,10,10, 10 and 3 the sum is 37. Subtracting 46 from 83 the difference is 37. We can check by adding 46 with 37 then the sum is 83.

Independent Practice

Find each difference. Use any strategy. Show your work.
Question 3.
62 – 21 = _______
Answer:
Envision-Math-Common-Core-Grade-2-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-49(1)
Explanation:
In the above image we can observe an equation 62 – 21 = ?. Here we are using compensation method to make numbers that are easier to subtract. Change both addends by subtracting the same amount. Then subtract using mental math. Subtract 1 from both numbers 62 and 21. Then the equation is 61 – 20 = ?. Subtract 20 from 61 then the difference is 41.

Question 4.
33 – 6 = _______
Answer:
Envision-Math-Common-Core-Grade-2-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-49(2)
Explanation:
In the above image we used a open number line. We can add up from 6 to subtract. First place 6 on the number line. Add 4 to get to 10. Then add 10, and 10 to get to 30. Then add 3 to land on 33. Add the tens and ones. By adding 4, 10, 10 and 3 the sum is 27. Subtracting 6 from 33 the difference is 27. We can check by adding 6 with 27 then the sum is 33.

Question 5.
94 – 45 = _______
Answer:
Envision-Math-Common-Core-Grade-2-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-49(3)
Explanation:
In the above image we can observe an equation 94 – 45 = ?. Here we are using compensation method to make numbers that are easier to subtract. Change both addends by adding the same amount. Then subtract using mental math. Add 5 to the addends 94 and 45. Then the equation is 99 – 50 = ?. Subtract 50 from 99 then the difference is 49.

Question 6.
55 – 18 = _______
Answer:
Envision-Math-Common-Core-Grade-2-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-49(4)
Explanation:
In the above image we used a open number line. We can add up from 18 to subtract. First place 18 on the number line. Add 2 to get to 20. Then add 10, 10, and 10 to get to 50. Then add 5 to land on 55. Add the tens and ones. By adding 2, 10, 10, 10 and 5 the sum is 37. Subtracting 18 from 55 the difference is 37. We can check by adding 18 with 37 then the sum is 55.

Question 7.
44 – 7 = _______
Answer:
Envision-Math-Common-Core-Grade-2-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-49(5)
Explanation:
In the above image we can observe an equation 44 – 7 = ?. Here we are using compensation method to make numbers that are easier to subtract. Change both addends by adding the same amount. Then subtract using mental math. Add 3 to the addends 44 and 7. Then the equation is 47 – 10 = ?. Subtract 10 from 47 then the difference is 17.

Question 8.
80 – 61 = _______
Answer:
Envision-Math-Common-Core-Grade-2-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-49(6)
Explanation:
In the above image we used a open number line. We can add up from 61 to subtract. First place 61 on the number line. Add 9 to get to 70. Then add 10 to land on 80. Add the tens and ones. By adding 9 and 10 the sum is 19. Subtracting 61 from 80 the difference is 19. We can check by adding 61 with 19 then the sum is 80.

Question 9.
77 – 9 = _______
Answer:
Envision-Math-Common-Core-Grade-2-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-49(7)
Explanation:
In the above image we can observe an equation 77 – 9 = ?. Here we are using compensation method to make numbers that are easier to subtract. Change both addends by adding the same amount. Then subtract using mental math. Add 1 to the addends 77 and 9. Then the equation is 78 – 10 = ?. Subtract 10 from 78 then the difference is 68.

Question 10.
100 – 55 = _______
Answer:
Envision-Math-Common-Core-Grade-2-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-49(8)
Explanation:
In the above image we can observe an equation 100 – 55 = ?. Here we are using compensation method to make numbers that are easier to subtract. Change both numbers by subtracting the same amount. Then subtract using mental math. Subtract 5 from both numbers 100 and 55. Then the equation is 95 – 50 = ?. Subtract 50 from 95 then the difference is 45.

Question 11.
72 – 48 = _______
Answer:
Envision-Math-Common-Core-Grade-2-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-49(9)
Explanation:
In the above image we used a open number line. We can add up from 48 to subtract. First place 48 on the number line. Add 2 to get to 50. Then add 10, and 10 to get to 70. Then add 2 to land on 72. Add the tens and ones. By adding 2, 10, 10, and 2 the sum is 24. Subtracting 48 from 72 the difference is 24. We can check by adding 48 with 24 then the sum is 72.

Number Sense Write the digit that makes each equation true.
Question 12.
5☐ – 6 = 47
Answer:
53 – 6 = 47
Explanation:
In the above equation the digit that make the equation true is 3. Subtract six from 53 then the difference is 47. The equation is 53 – 6 = 47.

Question 13.
☐4 – 28 = 56
Answer:
84 – 28 = 56
Explanation:
In the above equation the digit that make the equation true is 8. Subtract 28 from 84 then the difference is 56. The equation is 84 – 28 = 56.

Question 14.
61 – 1☐ = 46
Answer:
61 – 15 = 46
Explanation:
In the above equation the digit that make the equation true is 5. Subtract 15 from 61 then the difference is 46. The equation is 61 – 15 = 46.

Problem Solving

Use any strategy to solve each problem.
Question 15.
Luis has 31 stickers. Martin has 12 fewer stickers than Luis. Kaley has 45 stickers. How many stickers do Martin and Luis have in all? Do they have more or fewer stickers than Kaley? Explain.
_________ stickers
Circle:
more
fewer
Envision Math Common Core Grade 2 Answer Key Topic 5 Subtract Within 100 Using Strategies 50
Answer:
Envision-Math-Common-Core-Grade-2-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-50(1)
Luis and Martin have 43 stickers in all and Kaley have 45 stickers.
Luis and Martin have 2 fewer stickers than Kaley.
Explanation:
Luis has 31 stickers. Martin has 12 fewer stickers than Luis. Kaley has 45 stickers. First add 31 stickers and 12 stickers then the sum is 43 stickers in all. Luis and Martin have 2 fewer stickers than Kaley.

Question 16.
Kyle made 44 clay beads on Monday. On Tuesday, he made 8 fewer beads than he made on Monday. On Wednesday, he made 10 fewer beads than on Tuesday. How many beads did Kyle make on Wednesday?
_______ beads
Answer:
Kyle made 44 clay beads on Monday.
44 – 8 = 36
Kyle made 36 beads on Tuesday.
36 – 10 = 26
Kyle made 26 beads on Wednesday.
Explanation:
Kyle made 44 clay beads on Monday. On Tuesday, he made 8 fewer beads than he made on Monday. Subtract 8 beads from 44 beads then the difference is 36. Kyle made 36 beads on Tuesday. On Wednesday, he made 10 fewer beads than on Tuesday. Subtract 10 beads from 36 beads then the difference is 26. Kyle made 26 beads on Wednesday.

Question 17.
Assessment Practice Find the difference. 63 – 18 = ________
Explain how you solved the problem.
Answer:
Envision-Math-Common-Core-Grade-2-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-50(2)
2 + 10 + 10 + 10 + 10 + 3 = 45
63 – 18 = 45
Explanation:
In the above image we used a open number line. We can add up from 18 to subtract. First place 18 on the number line. Add 2 to get to 20. Then add 10, 10, 10 and 10 to get to 60. Then add 3 to land on 63. Add the tens and ones. By adding 2, 10, 10, 10, 10, and 3 the sum is 45. Subtracting 18 from 63 the difference is 45. We can check by adding 18 with 45 then the sum is 63.

Lesson 5.7 Solve One-Step and Two-Step Problems

Solve & Share
Some frogs were sitting on a pond. 16 more frogs joined them. Now there are 49 frogs on the pond. How many frogs were on the pond at first? Show how you know.
I can … solve one- and two-step problems using addition or subtraction.
Envision Math Common Core Grade 2 Answer Key Topic 5 Subtract Within 100 Using Strategies 51
Answer:
Envision-Math-Common-Core-Grade-2-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-51

33 frogs are there on the pond at first.
Explanation:
Some frogs were sitting on a pond. 16 more frogs joined them. Now there are 49 frogs on the pond. Subtract 16 frogs from 49 frogs. First break apart 16 into 10 and 6. Subtract 10 from 49 then the difference is 39. Next subtract the 6 frogs from 39 frogs then the difference is 33 frogs. At first 33 frogs are there on the pond.

Visual Learning Bridge
Envision Math Common Core Grade 2 Answer Key Topic 5 Subtract Within 100 Using Strategies 52

Convince Me! Cory scored some points. Then he scored 8 more points. He scored 14 points in all. How many points did Cory score at first? How can you solve the problem?
Answer:
Envision-Math-Common-Core-Grade-2-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-51(1)
Cory scored 6 points.
Explanation:
Cory scored some points. Then he scored 8 more points. He scored 14 points in all. Subtract 8 points from 14 points then the difference is 6. Cory scored 6 points.

Guided Practice

Complete both equations to solve the problem. Use the bar diagram to help you.
Question 1.
Some people got on the bus at the first stop. 9 more people got on the bus at the second stop. There are 21 people on the bus now. How many people got on the bus at the first stop?
Envision Math Common Core Grade 2 Answer Key Topic 5 Subtract Within 100 Using Strategies 53
Answer:
Envision-Math-Common-Core-Grade-2-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-53
At the first stop 12 people got on the bus.
Explanation:
Some people got on the bus at the first stop. 9 more people got on the bus at the second stop. There are 21 people on the bus now. Subtract 9 people from 21 people then the difference is 12 people. At the first stop 12 people got on the bus.

Independent Practice

Solve each problem. Show your work.
Question 2.
There are 24 peas on Kim’s plate. Kim eats 15 peas. Then Kim’s mother puts 8 more peas on her plate. How many peas are on Kim’s plate now?
Envision Math Common Core Grade 2 Answer Key Topic 5 Subtract Within 100 Using Strategies 54
__________ peas
Answer:
Envision-Math-Common-Core-Grade-2-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-54
There are 17 peas on Kim’s plate.
Explanation:
There are 24 peas on Kim’s plate. Kim eats 15 peas. Subtract 15 peas from 24 peas then the difference is 9 peas. Then Kim’s mother puts 8 more peas on her plate. Add 9 peas with 8 more peas then the sum is 17 peas. There are 17 peas on Kim’s plate.

Question 3.
Sue took out 5 books from the library on Monday. She took out 6 books from the library on Tuesday. Then she returned 3 books on Wednesday. How many books does Sue have on Thursday?
________ books
Answer:
5 + 6 = 11
11 – 3 = 8
Sue have 8 books on Thursday.
Explanation:
Sue took out 5 books from the library on Monday. She took out 6 books from the library on Tuesday. Add the books on Monday and Tuesday. Add 5 books with 6 books then the sum is 11 books. Now Sue have 11 books. Then she returned 3 books on Wednesday. Subtract 3 books from 11 books then the difference is  8 books. Sue have 8 books on Thursday.

Question 4.
Higher Order Thinking Mr. Wing’s class collected some cans to recycle on Tuesday. They collected 18 more cans : on Wednesday. The class collected 44 cans in all. How many cans did the class collect on Tuesday?
Envision Math Common Core Grade 2 Answer Key Topic 5 Subtract Within 100 Using Strategies 55
Answer:


The class collect 26 can on Tuesday.
Explanation:
Mr. Wing’s class collected some cans to recycle on Tuesday. They collected 18 more cans on Wednesday. The class collected 44 cans in all. Subtract 18 cans from 44 cans then the difference is 26 cans. The class collect 26 can on Tuesday.

Problem Solving

Write equations to solve the problems.
Envision Math Common Core Grade 2 Answer Key Topic 5 Subtract Within 100 Using Strategies 56

Question 5.
Make Sense Elaine put 13 photos in the album. Ken put some more photos in the album. There are 32 photos in the album in all. How many photos did Ken add?
_________ photos
Answer:
Envision-Math-Common-Core-Grade-2-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-55(1)
Ken add 19 more photos in the album.
Explanation:
Elaine put 13 photos in the album. Ken put some more photos in the album. There are 32 photos in the album in all. Subtract 13 photos from 32 photos then the difference is 19 photos. Ken add 19 more photos in the album.

Question 6.
Make Sense Kris sees some students in the library. Then 10 more students enter the library. Now Kris sees 20 students. How many students were in the library to start?
_________ students
Answer:
Envision-Math-Common-Core-Grade-2-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-55(2)
There are 10 students in the library to start.
Explanation:
Kris sees some students in the library. Then 10 more students enter the library. Now Kris sees 20 students. Subtract 10 students from 20 students then the difference is 10. There are 10 students in the library to start.

Question 7.
Higher Order Thinking There are 15 vocabulary words in Week I. There are 8 more vocabulary words in Week 2 than in Week I. How many words are there in both weeks?
Step 1: _______ + ________
Step 2: _______ + _________
_________ words
Answer:
Step 1: 15 + 8 = 23
Step 2: 23 + 15 = 38
38 words are there in both weeks.
Explanation:
There are 15 vocabulary words in Week I. There are 8 more vocabulary words in Week 2 than in Week I.
Step 1:
Add 15 words with 8 words then the sum is 23 words. In Week 2 there are 23 vocabulary words.
Step 2:
Add 15 words with 23 words then the sum is 38 words. 38 words are there in both weeks.

Question 8.
Assessment Practice Blake puts 8 marbles in the bag. Cole puts 9 marbles in the bag. Then Blake takes out 7 marbles from the bag. How many marbles are in the bag now? Solve. Show your work.
_________ marbles
Answer:
Step 1: 8 + 9 = 17
Step 2: 17 – 7 = 10
Now there are 10 marbles in the bag.
Explanation:
Blake puts 8 marbles in the bag. Cole puts 9 marbles in the bag. Then Blake takes out 7 marbles from the bag.
Step 1:
Add 8 marbles with 9 marbles then the sum is 17 marbles. Total number of marbles are 17.
Step 2:
Subtract 7 marbles from 17 marbles then the difference is 10 marbles. Now there are 10 marbles in the bag.

Lesson 5.8 Problem Solving

Critique Reasoning
Solve & Share
Bill collects and sells seashells. He has 45 shells, finds 29 shells, and sells 20 shells. How many seashells does Bill have now?
Tara says you have to subtract 45 – 29 and then add 20 to solve the problem. Do you agree with Tara’s thinking? Circle your answer. Use pictures, words, or equations to explain.
I can … critique the thinking of others by using what I know about addition and subtraction.
Envision Math Common Core Grade 2 Answer Key Topic 5 Subtract Within 100 Using Strategies 57
Answer:
Envision-Math-Common-Core-Grade-2-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-57

Bill have 54 seashells.
Explanation:
Bill collects and sells seashells. He has 45 shells, finds 29 shells, and sells 20 shells. First break apart 45 into 40 and 5 after that break 29 into 20 and 9. Add 40 with 20 then the sum is 60. Then add 5 with 9 then the sum is 14. Add these two numbers 60 and 14 then the sum is 74. Subtract 20 shells from 74 shells then the difference is 54 shells. Bill have 54 seashells. So Don’t agree with Tara’s thinking. So draw a circle for Do Not Agree.

Thinking Habits
What questions can I ask to understand other people’s thinking?
Are there mistakes in other people’s thinking?

Visual Learning Bridge
Envision Math Common Core Grade 2 Answer Key Topic 5 Subtract Within 100 Using Strategies 58

Convince Me! What question would you ask Kelly to help her check her reasoning?
Answer:
I could ask her for the total number of people swimming.

Guided Practice

Circle your answer. Use pictures, words, or equations to explain your reasoning.

Question 1.
51 people were on a train. 33 people left the train. How many people are on the train now?
Ryan says 18 people. He broke apart 33 into 30 and 3. Then he subtracted each number. Does Ryan’s reasoning make sense?
Envision Math Common Core Grade 2 Answer Key Topic 5 Subtract Within 100 Using Strategies 59
Answer:
Envision-Math-Common-Core-Grade-2-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-59
Now there are 18 people on the train.
Explanation:
51 people were on a train. 33 people left the train. Ryan says 18 people. He broke apart 33 into 30 and 3. Then he subtracted each number. I am agree with Ryan’s reasoning. First break apart 33 into 30 and 3. Subtract 30 from 51 then the difference is 21. Then subtract 3 from 21 then the difference is 18. There are 18 people on the train. So draw a circle for agree.

Independent Practice

Circle your answer. Use pictures, words, or equations to explain your reasoning.
Question 2.
Jill put 53 buttons in a box. Marci put 17 buttons in another box.
Jarod says Marci has 33 fewer buttons than Jill. He thinks 53 – 20 is easier to subtract than 53 – 17. He subtracts 53 – 20 and gets 33.
Do you agree or not agree with Jarod’s thinking?
Envision Math Common Core Grade 2 Answer Key Topic 5 Subtract Within 100 Using Strategies 59
Answer:
Envision-Math-Common-Core-Grade-2-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-59 (1)
Explanation:
Jill put 53 buttons in a box. Marci put 17 buttons in another box.
Jarod says Marci has 33 fewer buttons than Jill. He thinks 53 – 20 is easier to subtract than 53 – 17. He subtracts 53 – 20 and gets 33. I am agree with Jarod’s thinking because he forgot to add 3 to his answer.
First add 3 to 17 then the equation is 53 – 20 = ?. Subtract 20 from 53 then the difference is 33. Then add 3 to the 33 then the sum is 36. So draw a circle for Do Not Agree.

Question 3.
Rob has 68 more puzzle pieces than Gina. Rob has 90 puzzle pieces.
Carol says Gina has 22 puzzle pieces. Carol says she found 90 – 68 using an open number line. She added up 2 and 20 more from 68 and got 90.
Does Carol’s reasoning make sense?
Envision Math Common Core Grade 2 Answer Key Topic 5 Subtract Within 100 Using Strategies 59
Answer:
Envision-Math-Common-Core-Grade-2-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-59 (2)
Explanation:
Rob has 68 more puzzle pieces than Gina. Rob has 90 puzzle pieces.
Carol says Gina has 22 puzzle pieces. Carol says she found 90 – 68 using an open number line. She added up 2 and 20 more from 68 and got 90. Carol’s reasoning is correct. So draw a circle for Agree.
In the above image we used a open number line. We can add up from 68 to subtract. First place 68 on the number line. Add 2 to get to 70. Then add 10 to get to 80. Then add 10 to land on 90. Add the tens and ones. By adding 2, 10, and 10 the sum is 22. Subtracting 68 from 90 the difference is 22.

Problem Solving

Performance Task
Reading Books Ricky read the first 3 chapters of a book. Chapter 1 has 11 pages. Chapter 2 has 7 pages. Chapter 3 has 9 pages.
Sally read 46 pages of her book. How many more pages did Sally read than Ricky?
Envision Math Common Core Grade 2 Answer Key Topic 5 Subtract Within 100 Using Strategies 60
Question 4.
Make Sense What steps do you need to take to solve the problem?
Answer:
First I need to know how many pages Ricky read.

Question 5.
Look for a Pattern Is there a shortcut to find how many pages Ricky read? Explain.
Answer:
11 + 7 + 9 = ?
11 + 9 = 20
20 + 7 = 27
Ricky read 27 pages.
Explanation:
Ricky read the first 3 chapters of a book. Chapter 1 has 11 pages. Chapter 2 has 7 pages. Chapter 3 has 9 pages. Add 11 pages with 7 pages and 9 pages then we get the total number of pages. First add 11 pages with 9 pages then the sum is 20 pages. Add 9 pages with 20 pages then the sum is 27 pages. Ricky read 27 pages.

Question 6.
Explain Sally drew this open number line. Sally says she read 21 more pages than Ricky. Do you agree? Explain.
Envision Math Common Core Grade 2 Answer Key Topic 5 Subtract Within 100 Using Strategies 61
Answer:
Envision-Math-Common-Core-Grade-2-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-61
Explanation:
Sally read 46 pages of her book. Ricky read 27 pages. Sally says she read 21 more pages than Ricky. I am not agree with Sally answer. Subtract 27 pages from 46 pages then the difference is 19 pages.

Topic 5 Fluency Practice Activity

Find & Match
Find a partner. Point to a clue. Read the clue.
Look below the clues to find a match. Write the clue letter in the box next to the match.
Find a match for every clue.
I can … add and subtract within 20.

Clues
A. Every difference is 10.
B. Every sum is 11.
C. Every sum and difference is 6.
D. Exactly three sums are the same.
E. Exactly three differences are the same.
F. Every sum is the same as 9 + 4.
G. Every difference is odd.
H. Exactly three sums are even.
Envision Math Common Core Grade 2 Answer Key Topic 5 Subtract Within 100 Using Strategies 62
Answer:
Envision-Math-Common-Core-Grade-2-Answer-Key-Topic-5-Subtract-Within-100-Using-Strategies-62
Explanation:
In the above image we can observe the list below.
A. Every difference is 10.
10 – 0 = 10
20 – 10 = 10
14 – 4 = 10
19 – 9 = 10
B. Every sum is 11.
5 + 6 = 11
4 + 7 = 11
9 + 2 = 11
3 + 8 = 11
C. Every sum and difference is 6.
14 – 8 = 6
3 + 3 = 6
15 – 9 = 6
0 + 6 = 6
D. Exactly three sums are the same.
8 + 6 = 14
7 + 8 = 15
9 + 6 = 15
10 + 5 = 15
E. Exactly three differences are the same.
12 – 5 = 7
17 – 8 = 9
14 – 7 = 7
16 – 9 = 7
F. Every sum is the same as 9 + 4.
7 + 6 = 13
3 + 10 = 13
8 + 5 = 13
4 + 9 = 13
G. Every difference is odd.
15 – 8 = 7
18 – 9 = 9
12 – 7 = 5
13 – 6 = 7
H. Exactly three sums are even.
6 + 6 = 12
2 + 8 = 10
7 + 4 = 11
5 + 7 = 12

Topic 5 Vocabulary Review

Understand Vocabulary
Word List

  • break apart
  • compatible numbers
  • compensation
  • difference
  • mental math
  • ones
  • open number line
  • tens

Choose a term from the Word List to complete each sentence.
Question 1.
You can count back or add up to subtract on an ___________
Answer:
You can count back or add up to subtract on an open number line.

Question 2.
To find 42 – 7, you can ________ into 2 + 5.
Answer:
To find 42 – 7, you can break apart 7 into 2 + 5.

Question 3.
The answer to a subtraction problem is called the __________
Answer:
The answer to a subtraction problem is called the difference.

Question 4.
There are 6 ________ in the number 36.
Answer:
There are 6 ones in the number 36.

Question 5.
In 43, there are _______ tens.
Answer:
In 43, there are 4 tens.

Question 6.
In 76, there are _______ tens and ________ ones.
Answer:
In 76, there are  7 tens and 6 ones.

Question 7.
Break apart 8 to find 65 – 8.
Answer:
Break a part 8 into 5 + 3 to find 65 – 8.
65 – 5 = 60
60 – 3 = 57

Use Vocabulary in Writing
Question 8.
Use words to tell how to find 54 – 19. Use terms from the Word List.
Answer:
54  –  19
+1     +1
55  –  20  =  35
Explanation:
I can use compensation to add 1 to both numbers. I can use mental math to subtract 55 – 20 = 35.

Topic 5 Reteaching

Set A

You can use a hundred chart to help you subtract. Find 65 – 31.
Start at 31. Move right 4 ones to 35. Then move down 3 tens to 65. 3 tens and 4 ones is 34.
Envision Math Common Core Grade 2 Answers Topic 5 Subtract Within 100 Using Strategies 63

Use a hundred chart to solve the problems.
Question 1.
67 – 42 = _______
Answer:
Envision-Math-Common-Core-Grade-2-Answers-Topic-5-Subtract-Within-100-Using-Strategies-63(1)
Explanation:
In the above we can observe a hundred chart. Start at 42. Move right 5 ones to 47. Then move down 2 tens to 67. 2 tens and 5 ones is 25. By Subtracting 42 from 67 the difference is 25.

Question 2.
70 – 33 = ________
Answer:
Envision-Math-Common-Core-Grade-2-Answers-Topic-5-Subtract-Within-100-Using-Strategies-63(2)
Explanation:
In the above we can observe a hundred chart. Start at 33. Move right 7 ones to 40. Then move down 3 tens to 70. 3 tens and 7 ones is 37. By Subtracting 33 from 70 the difference is 37.

Question 3.
58 – 42 = _______
Answer:
Envision-Math-Common-Core-Grade-2-Answers-Topic-5-Subtract-Within-100-Using-Strategies-63(3)
Explanation:
In the above we can observe a hundred chart. Start at 42. Move right 6 ones to 48. Then move down 1 ten to 58. 1 ten and 6 ones is 16. Subtracting 42 from 58 the difference is 16.

Question 4.
63 – 38 = ________
Answer:
Envision-Math-Common-Core-Grade-2-Answers-Topic-5-Subtract-Within-100-Using-Strategies-63(4)
Explanation:
In the above we can observe a hundred chart. Start at 38. Move right 5 ones to 43. Then move down 2 tens to 63. 2 tens and 5 ones is 25. Subtracting 38 from 63 the difference is 25.

Set B

You can use an open number line to find 57 – 24.
Place 57 on the number line. 24 is 2 tens and 4 ones. So, you can count back by 10 two times. Then count back 4.
Envision Math Common Core Grade 2 Answers Topic 5 Subtract Within 100 Using Strategies 64

Use an open number line to find each difference.
Question 5.
38 – 13 = _________
Envision Math Common Core Grade 2 Answers Topic 5 Subtract Within 100 Using Strategies 65
Answer:
Envision-Math-Common-Core-Grade-2-Answers-Topic-5-Subtract-Within-100-Using-Strategies-65
38 – 13 = 25
Explanation:
In the above image we can observe a open number line. Place 38 on the number line. 13 is 1 ten and 3 ones. So, you can count back by 10 one times. Then count back 3. Then we land on 25. By subtracting 38 – 13 = 25.

Question 6.
93 – 36 = _______
Envision Math Common Core Grade 2 Answers Topic 5 Subtract Within 100 Using Strategies 65
Answer:
Envision-Math-Common-Core-Grade-2-Answers-Topic-5-Subtract-Within-100-Using-Strategies-65 (2)
93 – 36 = 57
Explanation:
In the above image we can observe a open number line. Place 93 on the number line. 36 is 3 ten and 6 ones. So, you can count back by 10 three times. Then count back 6. Then we land on 57. By subtracting 93 – 36 = 57.

Set C

Find 62 – 37.
Place 37 on the line. Then add up to 62. You can add 3 to get to 40. Then add two 10s to get to 60. Then add 2 to get to 62. Add the jumps of tens and ones: 3+ 10 + 10 + 2 = 25.
Envision Math Common Core Grade 2 Answers Topic 5 Subtract Within 100 Using Strategies 66

Add up on an open number line to find each difference.
Question 7.
75 – 47 = ________
Envision Math Common Core Grade 2 Answers Topic 5 Subtract Within 100 Using Strategies 65
Answer:
Envision-Math-Common-Core-Grade-2-Answers-Topic-5-Subtract-Within-100-Using-Strategies-65 (3)
75 – 47 = 28
Explanation:
In the above image we used a open number line. We can add up from 47 to subtract. First place 47 on the number line. Add 3 to get to 50. Then add 10, and 10 to get to 70. Then add 5 to land on 75. Add the tens and ones. By adding 3, 10, 10, and 5 the sum is 28. Subtracting 47 from 75 the difference is 28. We can check by adding 47 with 28 then the sum is 75.

Question 8.
52 – 29 = _________
Envision Math Common Core Grade 2 Answers Topic 5 Subtract Within 100 Using Strategies 65
Answer:
Envision-Math-Common-Core-Grade-2-Answers-Topic-5-Subtract-Within-100-Using-Strategies-65 (4)
52 -29 = 23
Explanation:
In the above image we used a open number line. We can add up from 29 to subtract. First place 29 on the number line. Add 1 to get to 30. Then add 10, and 10 to get to 50. Then add 2 to land on 52. Add the tens and ones. By adding 1, 10, 10, and 2 the sum is 23. Subtracting 29 from 52 the difference is 23. We can check by adding 29 with 23 then the sum is 52.

Set D

Break apart 7 to find 54 – 7.
Envision Math Common Core Grade 2 Answers Topic 5 Subtract Within 100 Using Strategies 67

Subtract. Break apart the number you are subtracting. Show your work.
Question 9.
52 – 6 = _______
Answer:
Envision-Math-Common-Core-Grade-2-Answers-Topic-5-Subtract-Within-100-Using-Strategies-67(1)
52 – 6 = 46
Explanation:
In the above image we can observe the subtracting number 6. Break apart 6 into 2 and 4. First subtract 2 from 52 then the difference is 50. Then subtract 4 from the difference 50 then the result is 46. By subtracting 6 from 52 the difference is 46.

Question 10.
45 – 9 = _________
Answer:
Envision-Math-Common-Core-Grade-2-Answers-Topic-5-Subtract-Within-100-Using-Strategies-67(2)
45 – 9 = 36
Explanation:
In the above image we can observe the subtracting number 9. Break apart 9 into 5 and 4. First subtract 5 from 45 then the difference is 40. Then subtract 4 from the difference 40 then the result is 36. By subtracting 9 from 45 the difference is 36.

Set E

74 – 27 = ?
Use compensation to solve.
Envision Math Common Core Grade 2 Answers Topic 5 Subtract Within 100 Using Strategies 68

Use compensation to subtract.
Question 11.
42 – 18 = _______
Answer:
42 – 18
+2
42 – 20 = 22
+2
42 – 20 = 24
42 – 18 = 24
Explanation:
In the above image we can observe an equation 42 – 18 = ?. Here we are using compensation method to make numbers that are easier to subtract. Add 2 to 18. Then the equation is 42 – 20 = ?. Then subtract using mental math. Subtract 20 from 42 then the difference is 22. Then add 2 to the answer 22. After adding 2 to the number 22 the sum is 24. By subtracting 18 from 42 the difference is 24.

Question 12.
84 – 37 = _______
Answer:
84 – 37
+3
84 – 40 = 44
+3
84 – 40 = 47
84 – 37 = 47
Explanation:
In the above image we can observe an equation 84 – 37 = ?. Here we are using compensation method to make numbers that are easier to subtract. Add 3 to 37. Then the equation is 84 – 40 = ?. Then subtract using mental math. Subtract 40 from 84 then the difference is 44. Then add 3 to the answer 44. After adding 3 to the number 44 the sum is 47. By subtracting 37 from 84 the difference is 47.

Set F

You can use different strategies and tools to subtract.
For example, you can:
Envision Math Common Core Grade 2 Answers Topic 5 Subtract Within 100 Using Strategies 69

Use any strategy to solve the problem. Show your work.
Question 13.
Lily has a puzzle with 8 fewer pieces than Jake has. Jake has 45 pieces. How many pieces does Lily have?
________ pieces
Answer:
45 – 8 = ?
45 – 8
+2
45 – 10 = 35
+2
45 – 10 = 37
45 – 8 = 37

Lily have 37 pieces.
Explanation:
Lily has a puzzle with 8 fewer pieces than Jake has. Jake has 45 pieces. In the above image we can observe an equation 45 – 8 = ?. Here we are using compensation method to make numbers that are easier to subtract. Add 2 to 8. Then the equation is 45 -10 = ?. Then subtract using mental math. Subtract 10 from 45 then the difference is 35. Then add 2 to the answer 35. After adding 2 to the number 35 the sum is 37. By subtracting 8 from 45 the difference is 37. Lily have 37 pieces.

Set G

Use the bar diagram and write two equations to model and solve the problem.
Mason read 34 pages in two days. He read 8 pages on Day 1. How many pages did he read on Day 2?
Envision Math Common Core Grade 2 Answers Topic 5 Subtract Within 100 Using Strategies 70
Answer:
Manson read 26 pages on Day 2.
Explanation:
Mason read 34 pages in two days. He read 8 pages on Day 1. Subtract 8 pages from 34 pages then the difference is 26. Manson read 26 pages on Day 2.

Add or subtract to solve the problem. Show your work.
Question 14.
Gene bakes 60 muffins in one day. He bakes 24 of the muffins before lunch. How many muffins does he bake after lunch?
Envision Math Common Core Grade 2 Answers Topic 5 Subtract Within 100 Using Strategies 71
________ muffins
Answer:
Envision-Math-Common-Core-Grade-2-Answers-Topic-5-Subtract-Within-100-Using-Strategies-71
Gene bakes 36 muffins after lunch.
Explanation:
Gene bakes 60 muffins in one day. He bakes 24 of the muffins before lunch as we can observe in the above image. Subtract 24 muffins from 60 muffins then the difference is 36 muffins. Gene bakes 36 muffins after lunch.

Set H

Thinking Habits
Critique Reasoning
What questions can I ask to understand other people’s thinking?
Are there mistakes in other people’s thinking?
Envision Math Common Core Grade 2 Answers Topic 5 Subtract Within 100 Using Strategies 72

Do you agree or disagree? Explain.
Question 15.
Ken has 29 more stamps than Jamie. Ken has 52 stamps. Lisa says Jamie has 23 stamps.
Lisa added up from 29, then 20 more from 30, and 2 more to get to 52. Does Lisa’s reasoning make sense?
Answer:
Envision-Math-Common-Core-Grade-2-Answers-Topic-5-Subtract-Within-100-Using-Strategies-71(1)
I agree with Lisa’s reasoning.
Explanation:
Ken has 29 more stamps than Jamie. Ken has 52 stamps. Lisa says Jamie has 23 stamps. Lisa added up from 29, then 20 more from 30, and 2 more to get to 52. I agree with Lisa’s reasoning.
In the above image we used a open number line. We can add up from 29 to subtract. First place 29 on the number line. Add 1 to get to 30. Then add 10, and 10 to get to 50. Then add 2 to land on 52. Add the tens and ones. By adding 1, 10, 10, and 2 the sum is 23. Subtracting 29 from 52 the difference is 23. Jamie has 23 stamps.

Topic 5 Assessment Practice

Question 1.
A store has 68 candles. Then they sell 29 of the candles. 6 candles are returned. How many candles do they have now?
A. 39
B. 33
C. 45
D. 97
Answer:
68 – 29 = 39
39 + 6 = 45
Now they have 45 candles. So option C is correct.
Explanation:
A store has 68 candles. Then they sell 29 of the candles. 6 candles are returned. Subtract 29 candles from 68 candles then the difference is 39. Add 39 candles with 6 candles then the sum is 45. They have 45 candles. So option C is correct.

Question 2.
Claire thinks this number line models 48 + 30 = 78. She thinks 3 tens have been added to 48. Is she correct? Choose the correct explanation.
Envision Math Common Core Grade 2 Answers Topic 5 Subtract Within 100 Using Strategies 73
A. No. The number line shows starting at 48 and counting back 3 tens.
B. Yes. The number line shows starting at 48 and counting on 3 tens.
C. No. The number line shows starting at 38 and counting back 3 tens.
D. No. The number line shows starting at 48 and counting back 4 tens.
Answer:
Claire is not correct. So option A is correct answer.

Question 3.
Tony has 66 rocks. He gives 23 rocks to Chris.
How many rocks does Tony have now? Write an equation to show your work and solve.
Envision Math Common Core Grade 2 Answers Topic 5 Subtract Within 100 Using Strategies 74
Answer:
Envision-Math-Common-Core-Grade-2-Answers-Topic-5-Subtract-Within-100-Using-Strategies-74
Now Tony have 43 rocks.
Explanation:
Tony has 66 rocks. He gives 23 rocks to Chris. In the above we can observe a hundred chart. Start at 23. Move right 3 ones to 26. Then move down 4 tens to 66. 4 tens and 3 ones is 43. By Subtracting 23 from 66 the difference is 43. Tony have 43 rocks.

Question 4.
Which is the difference of 34 – 7?
A. 26
B. 27
C. 28
D. 29
Answer:
34 – 7 = 27
Option B is correct.

Question 5.
Keena has 64 balloons. 28 of the balloons are red. 14 balloons are green. The rest of the balloons are purple. How many of the balloons are purple?
A. 22
B. 36
C. 42
D. 50
Answer:
28 + 14 + ? = 64
42 + ? = 64
64 – 42 = 22
There are 22 purple balloons. Option A is correct.
Explanation:
Keena has 64 balloons. 28 of the balloons are red. 14 balloons are green. The rest of the balloons are purple. First add 28 red balloons with 14 green balloons then the sum is 42 balloons. Subtract 42 balloons from 64 balloons then the difference is 22. There are 22 purple balloons.

Question 6.
Joe has 43 stickers. Then he gives away 9 stickers. Which equations can be used to find how many stickers Joe has left?
A. 43 + 7 = 50 and 50 + 2 = 52
B. 43 + 10 = 53 and 53 – 1 = 52
C. 43 – 3 = 40 and 40 + 6 = 46
D. 43 – 10 = 33 and 33 + 1 = 34
Answer:
43 – 9
+1
43 – 10 = 33
+1
43 – 10 = 34
Option D is correct.
Explanation:
In the above image we can observe an equation 43 – 9 = ?. Here we are using compensation method to make numbers that are easier to subtract. Add 1 to 9. Then the equation is 43 – 10 = ?. Then subtract using mental math. Subtract 10 from 43 then the difference is 33. Then add 1 to the answer 33. After adding 1 to the number 33 the sum is 34. By subtracting 9 from 43 the difference is 34.

Question 7.
Subtract. Break apart the number you are subtracting. Show your work.
73 – 6 = ?
73 – 6 = _________
Answer:
Break 6 into 3 and 3
73 – 3 = 70
70 – 3 = 67
73 – 6 = 67
Explanation:
Break apart 6 into 3 and 3. Subtract 3 from 73 then the difference is 70. After that subtract 3 from 70 the difference is 67. By subtracting 6 from 73 the difference is 67.

Question 8.
A. Write the equation that the number line shows.
Answer:
82 – 50 = 32
Explanation:
In the below image we can observe open number line. Place 82 on the number line. Then count back 10 three times then we land on 52. Count back 2 ones we land on 50. Add the numbers 2, 10, 10, 10 is equal to 32. By subtracting 50 from 82 the difference is 32.

B. Then, explain what the jumps are showing.
Envision Math Common Core Grade 2 Answers Topic 5 Subtract Within 100 Using Strategies 75
Answer:
Envision-Math-Common-Core-Grade-2-Answers-Topic-5-Subtract-Within-100-Using-Strategies-75
In the above image we can observe the jumps. The jumps are 10, 10, 10, 2.

Question 9.‌
The‌ ‌number‌ ‌line‌ ‌below‌ ‌shows‌ ‌adding‌ ‌up‌ ‌to‌ ‌subtract‌ ‌to‌ ‌find‌ ‌68‌ ‌–‌ ‌36.‌ ‌What‌ ‌is‌ ‌the‌ ‌difference?‌ ‌Explain‌ ‌how‌ ‌you‌ ‌know.‌ ‌
Envision Math Common Core Grade 2 Answers Topic 5 Subtract Within 100 Using Strategies 76
Answer:
68 – 36 = 32
Explanation:
In the above image we used a open number line. We can add up from 36 to subtract. First place 36 on the number line. Add 10, 10 and 10 to get to 66. Then add 2 to land on 68. Add the tens and ones. By adding 10, 10, 10, and 2 the sum is 32. Subtracting 36 from 68 the difference is 32.

Question 10.
‌ ‌Use‌ ‌the‌ ‌open‌ ‌number‌ ‌line‌ ‌to‌ ‌find‌ ‌the‌ ‌difference.‌ ‌
80‌ ‌–‌ ‌42‌ ‌=‌ ‌?‌ ‌
80‌ ‌–‌ ‌42‌ ‌=‌ ‌ ________
Answer:
Envision-Math-Common-Core-Grade-2-Answers-Topic-5-Subtract-Within-100-Using-Strategies-75(1)
80 – 42 = 38
Explanation:
In the above image we used a open number line to find the difference. First place 80 on the line. The subtracting number 42 is 4 tens and 2 ones. So, count back 4 tens from 80. The numbers are 70, 60, 50, 40. Then count back 2 ones from 40. The number is 38. By subtracting 42 from 80 the difference is 38.

Question 11.
‌A.‌ ‌33‌ ‌ants‌ ‌are‌ ‌on‌ ‌a‌ ‌leaf.‌ ‌15‌ ‌ants‌ ‌leave.‌ ‌ How‌ ‌many‌ ‌ants‌ ‌are‌ ‌left?‌ ‌Jay‌ ‌adds‌ ‌2‌ ‌to‌ ‌33‌ ‌to‌ ‌make‌ ‌an‌ ‌easier‌ ‌problem,‌ ‌35‌ ‌–‌ ‌15.‌ ‌ He‌ ‌says‌ ‌20‌ ‌ants‌ ‌are‌ ‌left.‌ ‌Circle‌ ‌whether‌ ‌you‌ ‌agree‌ ‌or‌ ‌do‌ ‌not‌ ‌agree.‌ ‌
Agree‌ ‌
Do‌ ‌Not‌ ‌Agree‌ ‌
Answer:
Envision-Math-Common-Core-Grade-2-Answers-Topic-5-Subtract-Within-100-Using-Strategies-75(2)
33 – 15 = 18
18 ants are left.
‌I am not agree with Jay thinking.

B.‌ ‌Explain‌ ‌why‌ ‌you‌ ‌agree‌ ‌or‌ ‌do‌ ‌not‌ ‌agree‌ ‌with‌ ‌Jay’s‌ ‌strategy.‌ ‌
Answer:
33‌ ‌ants‌ ‌are‌ ‌on‌ ‌a‌ ‌leaf.‌ ‌15‌ ‌ants‌ ‌leave.‌ ‌Jay‌ ‌adds‌ ‌2‌ ‌to‌ ‌33‌ ‌to‌ ‌make‌ ‌an‌ ‌easier‌ ‌problem,‌ ‌35‌ ‌–‌ ‌15.‌ ‌ He‌ ‌says‌ ‌20‌ ‌ants‌ ‌are‌ ‌left.‌ The equation is 33 – 15 = ?. Here we are using compensation method to make numbers that are easier to subtract. Subtract 2 from 15. Then the equation is 33 – 13 = ?. Then subtract using mental math. Subtract 13 from 33 then the difference is 20. Then subtract 2 from the answer 20. After subtracting 2 from the number 20 the difference is 18. By subtracting 15 from 33 the difference is 18.

Question 12.
Use the open number lines. Show two different ways to find 74 – 28. Show your work.
One Way
74 – 28 = ________

Another Way
74 – 28 = _________
Answer:
One way
Envision-Math-Common-Core-Grade-2-Answers-Topic-5-Subtract-Within-100-Using-Strategies-75(3)
74 – 28 = 46
Explanation:
In the above image we used a open number line to find the difference. First place 74 on the line. The subtracting number 28 is 2 tens and 8 ones. So, count back 2 tens from 74. The numbers are 64, 54. Then count back 8 ones from 54. The number is 46. By subtracting 28 from 74 the difference is 46.
Another way
Envision-Math-Common-Core-Grade-2-Answers-Topic-5-Subtract-Within-100-Using-Strategies-75(4)
74 – 28 = 46
In the above image we used a open number line to find the difference. First place 74 on the line. The subtracting number 28 is 2 tens and 8 ones. So, count back 2 tens from 74. The number is 54. Then count back 8 ones from 54. The number is 46. By subtracting 28 from 74 the difference is 46.

Question 13.
Use the numbers on the cards. Write the missing numbers to solve the problem. What strategy did you use to solve the problem? Explain.
Envision Math Common Core Grade 2 Answers Topic 5 Subtract Within 100 Using Strategies 77
Answer:
Envision-Math-Common-Core-Grade-2-Answers-Topic-5-Subtract-Within-100-Using-Strategies-77
The missing numbers are 3, 75, 40, 35.
Explanation:
In the above image we can observe an equation 72 – 37 = ?. Here we are using compensation method to make numbers that are easier to subtract. Change both addends by adding the same amount. Then subtract using mental math. Add 3 to the addends 72 and 37. Then the equation is 75 – 40 = ?. Subtract 40 from 75 then the difference is 35.

Question 14.
5 black cows are at the ranch. 9 brown cows join them. Then 6 cows leave the ranch. How many cows are still at the ranch? Solve. Show your work.
Step 1

Step 2

Answer
________ cows
Answer:
Step 1: 5 + 9 = 14
Step 2: 14 – 6 = 8
8 cows are still at the ranch.
Explanation:
5 black cows are at the ranch. 9 brown cows join them. Then 6 cows leave the ranch. First add black cows with 9 brown cows then the sum is 14 cows. Subtract 6 cows from 14 cows the difference is 8. 8 cows are still at the ranch.

Topic 5 Performance Task

Beautiful Boats
Chen’s family goes to the lake for a vacation. They count the boats that they see.
Envision Math Common Core Grade 2 Answers Topic 5 Subtract Within 100 Using Strategies 78
Question 1.
How many more motorboats does Chen see than sailboats?
Use the open number line to solve.
Envision Math Common Core Grade 2 Answers Topic 5 Subtract Within 100 Using Strategies 79
________ more motorboats
Answer:
Envision-Math-Common-Core-Grade-2-Answers-Topic-5-Subtract-Within-100-Using-Strategies-79
36 – 12 = 24
Chen see 24 motorboats than sailboats.
Explanation:
Chen’s family goes to the lake for a vacation. They see 12 sailboats, 28 rowboats, 36 motorboats. In the above image we used a open number line to find the difference. First place 36 on the line. The subtracting number 12 is 1 ten and 2 ones. So, count back 1 ten from 36. The number is 26. Then count back 2 ones from 26. The number is 24. By subtracting 12 from 36 the difference is 24. Chen see 24 motorboats than sailboats.

Question 2.
Maria’s family saw 57 rowboats on their vacation. How many more rowboats did they see than Chen’s family?
Use compensation to solve. Explain how you found your answer.
__________ more rowboats
Answer:
Envision-Math-Common-Core-Grade-2-Answers-Topic-5-Subtract-Within-100-Using-Strategies-79(1)
Maria’s family saw 29 more rowboats than Chen’s family.
Explanation:
In the above image we can observe an equation 57 – 28= ?. Here we are using compensation method to make numbers that are easier to subtract. Add 2 to 28. Then the equation is 57 – 30 = ?. Then subtract using mental math. Subtract 30 from 57 then the difference is 27. Then add 2 to the answer 29. After adding 2 to the number 27 the sum is 29. By subtracting 28 from 57 the difference is 29. Maria’s family saw 29 more rowboats than Chen’s family.

Question 3.
Chen’s sisters have toy boats. They have 21 yellow boats. They have 9 fewer red boats than yellow boats. How many boats do they have in all?
Choose any strategy. Show your work.
________ boats
Answer:
21 – 9 = 12
They have 12 red boats.
21 + 12 = 33
They have 33 boats in all.
Explanation:
Chen’s sisters have toy boats. They have 21 yellow boats. They have 9 fewer red boats than yellow boats. First subtract 9 boats from 21 boats then the difference is 12 boats. They have 12 red boats. Add 21 yellow boats with 12 red boats then the sum is 33 boats. They have 33 boats in all.

Question 4.
Julie’s family saw 94 boats on their vacation. How many more boats did they see than Chen’s family?
Part A
What do you need to do to solve the problem?
Answer:
We need how many boats does Chen’s family see on their vacation.

Part B
How many boats did Chen see? Show your work. Then explain how you found your answer.
________ boats
Answer:
12 sailboats + 28 Rowboats + 36 Motorboats = 76 boats
Chen’s family saw 76 boats on their vacation.
Explanation:
Add 12 sailboats with 28 Rowboats and 36 Motorboats then the sum is 76 boats. Chen’s family saw 76 boats on their vacation.

Part C
Julie said that her family saw 18 more boats than Chen’s family. She broke apart 76 into 70 + 4 + 2. Then she subtracted each number from 94. Does Julie’s reasoning make sense? Explain.
Answer:
Break 76 into 70 + 4 + 2
94 – 70 = 24
24 – 4 = 20
20 – 2 = 18
Yes Julie’s reasoning is correct. Julie family saw 18 more boats than Chen’s family.
Explanation:
Julie said that her family saw 18 more boats than Chen’s family. She broke apart 76 into 70 + 4 + 2. Then she subtracted each number from 94. Yes Julie’s reasoning is correct. First subtract 70 from 94 then the difference is 24. Subtract 4 rom 24 the difference is 20. Subtract 2 from 20 then the difference is 18. Julie family saw 18 more boats than Chen’s family.

enVision Math Common Core Grade 2 Answer Key Topic 4 Fluently Add Within 100

Practice with the help of enVision Math Common Core Grade 2 Answer Key Topic 4 Fluently Add Within 100 regularly and improve your accuracy in solving questions.

enVision Math Common Core 2nd Grade Answers Key Topic 4 Fluently Add Within 100

Essential Question:
What are strategies for adding numbers to 100?
Envision Math Common Core 2nd Grade Answer Key Topic 4 Fluently Add Within 100 1

enVision STEM Project: Making and Using Models
Find Out Find and share books about Hawaii and volcanoes. Make a model of a volcano that becomes an island. Tell about how the island can change over a long time.
Journal: Make a Book Show what you learn in a book. In your book, also:

  • Draw pictures to show how volcanoes can become islands.
  • Show how you can use models to help you add numbers to 100.

Review What You Know

Vocabulary
Question 1.
Circle the tens digit in each number.
73
53
82
Answer:
The tens digit in each number is 7,5 and 8.

Explanation:
Given that the digits are 73, 53, 82. So the tens digit in each number is 7,5 and 8.

Question 2.
Circle the ones digit in each number.
34
43
97
Answer:
The ones digit in each number is 4,3 and 7.

Explanation:
Given that the digits are 73, 53, 82. So the one digit in each number is 4,3 and 7.

Question 3.
Break apart 23 into tens and ones.
23 = _________ tens and ______ ones
Answer:
23 = 2 tens and 3 ones.

Explanation:
Given that the number is 23, so after a break apart of 23 it will be 2 tens and 3 ones.

Mental Math
Question 4.
Use mental math to find each sum.
34 + 10 = _________
50 + 5 = _________
20 + 40 = _________
Answer:
44, 55, 60.

Explanation:
The sum of
34 + 10 = 44
50 + 5 = 55
20 + 40 = 60.

Open Number Line
Question 5. Use the open number line to find 39 + 15.
Envision Math Common Core 2nd Grade Answer Key Topic 4 Fluently Add Within 100 2
39 + 15 = _________
Answer:

Math Story
Question 6.
Stacy has 17 marbles. Diana gives her 22 marbles. How many marbles does Stacy have now?
______ marbles
Answer:
The number of marbles does Stacy has now is 39 marbles.

Explanation:
Given that Stacy has 17 marbles and Diana gives her 22 marbles. So the number of marbles does Stacy has now is 17 + 22 which is 39 marbles.

Pick a Project

PROJECT 4A
Where can you bike near home?
Project: Make a Bike Trail Brochure
Envision Math Common Core 2nd Grade Answer Key Topic 4 Fluently Add Within 100 3

PROJECT 4B
What kinds of coral grow in Florida?
Project: Build a Coral Model
Envision Math Common Core 2nd Grade Answer Key Topic 4 Fluently Add Within 100 4

PROJECT 4C
What do you collect?
Project: Display a Rock and Leaf Collection
Envision Math Common Core 2nd Grade Answer Key Topic 4 Fluently Add Within 100 5

PROJECT 4D
How much does it cost to visit the Kennedy Space Center?
Project: Make a Space Center Poster
Envision Math Common Core 2nd Grade Answer Key Topic 4 Fluently Add Within 100 6

Lesson 4.1 Add 2-Digit Numbers Using Models

Solve & Share
Leslie collects 36 rocks. Her brother collects 27 rocks. How many rocks do they collect in all? Use place-value blocks to help you solve. Show your place-value blocks.
I can … use models to add 2-digit numbers and then explain my work.
Envision Math Common Core 2nd Grade Answer Key Topic 4 Fluently Add Within 100 7

Visual Learning Bridge
Envision Math Common Core 2nd Grade Answer Key Topic 4 Fluently Add Within 100 8

Convince Me! When do you need to regroup when adding?

Guided Practice

Add. Use place-value blocks to find each sum. Regroup if needed.
Question 1.
32 + 29 = ________
Envision Math Common Core 2nd Grade Answer Key Topic 4 Fluently Add Within 100 9
_______ tens ______ ones
Answer:
6 tens and 1 ones.

Explanation:
Given that the sum of 32 + 29 is 61. So there are 6 tens and 1 one.

Question 2.
24 + 52 = _______
Envision Math Common Core 2nd Grade Answer Key Topic 4 Fluently Add Within 100 10
_______ tens ______ ones
Answer:
7 tens and 6 ones.

Explanation:
Given that the sum of 24 + 52 is 76. So there are 7 tens and 6 ones.

Question 3.
15 + 38 = _______
Envision Math Common Core 2nd Grade Answer Key Topic 4 Fluently Add Within 100 11
_______ tens ______ ones
Answer:
5 tens and 3 ones.

Explanation:
Given that the sum of 15 + 38 is 53. So there are 5 tens and 3 ones.

Independent Practice

Add. Use place-value blocks to find each sum. Regroup if needed.
Question 4.
36 + 29 = _______
Answer:
6 tens and 5 ones.

Explanation:
Given that the sum of 36 + 29 is 65. So there are 6 tens and 5 ones.

Question 5.
27 + 23 = _______
Answer:
5 tens and 0 ones.

Explanation:
Given that the sum of 27 + 23 is 50. So there are 5 tens and 0 ones.

Question 6.
59 + 13 = _______
Answer:
7 tens and 2 ones.

Explanation:
Given that the sum of 59 + 13 is 72. So there are 7 tens and 2 ones.

Question 7.
24 + 35 = _______
Answer:
5 tens and 9 ones.

Explanation:
Given that the sum of 24 + 35 is 59. So there are 5 tens and 9 ones.

Question 8.
58 + 25 = _______
Answer:
8 tens and 3 ones.

Explanation:
Given that the sum of 58 + 25 is 83. So there are 8 tens and 3 ones.

Question 9.
15+ 46 = _______
Answer:
6 tens and 1 one.

Explanation:
Given that the sum of 15 + 46 is 61. So there are 6 tens and 1 one.

Question 10.
75 + 19 = ________
Answer:
9 tens and 4 ones.

Explanation:
Given that the sum of 75 + 19 is 94. So there are 9 tens and 4 ones.

Question 11.
44 + 47 = _______
Answer:
9 tens and 1 one.

Explanation:
Given that the sum of 44 + 47 is 91. So there are 9 tens and 1 one.

Higher Order Thinking Read the sum. Circle all of the number pairs in the box that match that sum.
Question 12.
Envision Math Common Core 2nd Grade Answer Key Topic 4 Fluently Add Within 100 12
Answer:
12 + 10 = 22
18 + 4 = 22.

Explanation:
The number pairs to get the sum as 22 are 12 + 10 and 18 + 4.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-4-Fluently-Add-Within-100-12-1

Question 13
Envision Math Common Core 2nd Grade Answer Key Topic 4 Fluently Add Within 100 13
Answer:
25 + 30
45 + 10.

Explanation:
The number pairs to get the sum as 55 are 25 + 30 and 45 + 10.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-4-Fluently-Add-Within-100-13-1

Question 14.
Envision Math Common Core 2nd Grade Answer Key Topic 4 Fluently Add Within 100 14
Answer:
56 + 27
19 + 64.

Explanation:
The number pairs to get the sum as 83 are 56 + 27 and 19 + 64.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-4-Fluently-Add-Within-100-14-1

Problem Solving

Solve the problems below. Show your work.
Question 15.
Model Chen counts 47 buttons. Then he counts 20 more buttons. How many buttons does Chen count in all?
________ buttons
Answer:
The total number of buttons does Chen count in all is 67 buttons.

Explanation:
Given that Chen counts 47 buttons and then he counts 20 more buttons. So the total number of buttons does Chen count in all is 47 + 20 which is 67 buttons.

Question 16.
en Vision® STEM There were 24 earthquakes in the U.S. one year. There were 28 earthquakes the next year. How many earthquakes were there in those two years?
________ earthquakes
Answer:
The number of earthquakes in those two years is 52 earthquakes.

Explanation:
Given that there were 24 earthquakes in the U.S in one year and in other year there were 28 earthquakes the next year. So the number of earthquakes is 24 + 28 which is 52 earthquakes.

Question 17.
Higher Order Thinking Write an addition story about the desks and chairs in your classroom. Use pictures, numbers, or words.
Answer:

Question 18.
Assessment Practice Do you have to regroup to find each sum? Choose Yes or No.
Envision Math Common Core 2nd Grade Answer Key Topic 4 Fluently Add Within 100 15
Answer:

Lesson 4.2 Continue to Add 2-Digit Numbers Using Models

Solve & Share
Wendy picked 35 pears. Toni picked 49 pears. How many pears did they pick in all? Use place-value blocks to help explain your work.
I can … add numbers using place value and properties of operations.
Envision Math Common Core 2nd Grade Answer Key Topic 4 Fluently Add Within 100 16

Answer:
The total number of pears that they picked up is 84 pears.

Explanation:
Given that Wendy picked 35 pears andToni picked 49 pears. So the total number of pears that they picked up is 35 + 49 which is 84 pears.
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-4-Fluently-Add-Within-100-16-1

Visual Learning Bridge
Envision Math Common Core 2nd Grade Answer Key Topic 4 Fluently Add Within 100 17

Convince Me! Ken adds 43 + 27. His sum is 60. Is he correct? Explain.

Answer:
No, Ken is not correct.

Explanation:
No, Ken is not correct, because 43 + 27 is 70 but he got the sum as 60.

Guided Practice

Add. Use place value. Draw blocks or use another way.
Question 1.
12 + 23 = ________
Envision Math Common Core 2nd Grade Answer Key Topic 4 Fluently Add Within 100 18

Answer:
The sum of 12 + 23 is 35.

Explanation:
The sum of
12
+23
——
30
5
——
35

Question 2.
18 + 42 = _______
Envision Math Common Core 2nd Grade Answer Key Topic 4 Fluently Add Within 100 19
Answer:
The sum of 18 + 42 is 60.

Question 3.
33 + 48 = ________
Answer:
The sum of 33 +48 is 81

Explanation:
The sum of
33
+48
——
70
11
——
81

Independent Practice

Add. Use place value. Draw blocks or use another way.
Question 4.
18 + 24 = ________
Answer:
The sum of 18 + 24 is 42

Explanation:
The sum of
18
+24
——
30
12
——
42

Question 5.
47 + 38 = ________
Answer:
The sum of 47 + 38 is 85

Explanation:
The sum of
47
+38
——
70
15
——
85

Question 6.
26 + 47 = ________
Answer:
The sum of 26 + 47 is 73

Explanation:
The sum of
26
+47
——
60
13
——
73

Question 7.
34 + 58 = ________
Answer:
The sum of 34 + 58 is 92

Explanation:
The sum of
34
+58
——
80
12
——
92

Question 8.
Higher Order Thinking Draw the second addend.
Envision Math Common Core 2nd Grade Answer Key Topic 4 Fluently Add Within 100 20
Answer:

Problem Solving

Solve each problem. Show your work.
Question 9.
Toby planted 28 trees. Juan planted 36 trees. How many trees did they plant in all?
________ trees
Answer:
The number of trees did they plant in all is 64 trees.

Explanation:
Given that Toby planted 28 trees and Juan planted 36 trees. So the number of trees did they plant in all is 28 + 36 which is 64 trees.

Question 10.
Make Sense Jenny has 13 tennis balls. Sal had 16 tennis balls, but he gave 7 of them to Joe. How many tennis balls do Jenny and Sal have now?
________ tennis balls
Answer:
The number of tennis balls does Jenny and Sal have now is 22 tennis balls.

Explanation:
Given that Jenny has 13 tennis balls and Sal had 16 tennis balls. So the total number of tennis balls is 13 + 16 = 29. He gave 7 of them to Joe, so the number of tennis balls do Jenny and Sal have now is 29 – 7 which is 22 tennis balls.

Question 11.
Higher Order Thinking Write an addition story using two 2-digit numbers. Then solve the problem for your story.
Answer:

Question 12.
Assessment Practice which is the same amount as 28 + 16? Choose all that apply.
Envision Math Common Core 2nd Grade Answer Key Topic 4 Fluently Add Within 100 21
Answer:

Lesson 4.3 Add with Partial Sums

Solve & Share
Ms. Kim’s class has 25 students. Mr. Will’s class has 36 students. Both classes go on a field trip. How many students are on the trip?
Draw place-value blocks to help you solve the problem.
I can … add using place value and partial sums.
___________ students

Visual Learning Bridge
Envision Math Common Core 2nd Grade Answer Key Topic 4 Fluently Add Within 100 22

Convince Me! Can you add the ones first and then the tens | when finding 57 + 28 using partial sums? Explain.

Guided Practice

Add. Use partial sums. Draw blocks if you need to.
Question 1.
24 + 13
Envision Math Common Core 2nd Grade Answer Key Topic 4 Fluently Add Within 100 23
Answer:
The sum of the given numbers is 37.

Explanation:
Given that the numbers to add is 24 and 13. Now we will perform a partial sum of those numbers,
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-4-Fluently-Add-Within-100-23-1

Question 2.
68 + 7
Envision Math Common Core 2nd Grade Answer Key Topic 4 Fluently Add Within 100 24
Answer:
The sum of the given numbers is 75.

Explanation:
Given that the numbers to add is 68 and 7. Now we will perform a partial sum of those numbers,
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-4-Fluently-Add-Within-100-24-1

Independent Practice

Add. Use partial sums. Draw blocks if you need to.
Question 3.
34 + 25
Envision Math Common Core 2nd Grade Answer Key Topic 4 Fluently Add Within 100 25
Answer:
The sum of the given numbers is 59.

Explanation:
Given that the numbers to add is 34 and 25. Now we will perform a partial sum of those numbers,
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-4-Fluently-Add-Within-100-25Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-4-Fluently-Add-Within-100-25Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-4-Fluently-Add-Within-100-25Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-4-Fluently-Add-Within-100-25Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-4-Fluently-Add-Within-100-25-1

Question 4.
68 + 18
Envision Math Common Core 2nd Grade Answer Key Topic 4 Fluently Add Within 100 26
Answer:
The sum of the given numbers is 86.

Explanation:
Given that the numbers to add is 68 and 18. Now we will perform a partial sum of those numbers,

Question 5.
37 + 8
Envision Math Common Core 2nd Grade Answer Key Topic 4 Fluently Add Within 100 27
Answer:
The sum of the given numbers is 45.

Explanation:
Given that the numbers to add is 37 and 8. Now we will perform a partial sum of those numbers,
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-4-Fluently-Add-Within-100-27-1

Question 6.
52 + 38
Envision Math Common Core 2nd Grade Answer Key Topic 4 Fluently Add Within 100 28
Answer:
The sum of the given numbers is 90.

Explanation:
Given that the numbers to add is 52 and 38. Now we will perform a partial sum of those numbers,
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-4-Fluently-Add-Within-100-28-1Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-4-Fluently-Add-Within-100-28-1Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-4-Fluently-Add-Within-100-28-1Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-4-Fluently-Add-Within-100-28-1Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-4-Fluently-Add-Within-100-28-1

Question 7.
45 + 29
Envision Math Common Core 2nd Grade Answer Key Topic 4 Fluently Add Within 100 29
Answer:
The sum of the given numbers is 74.

Explanation:
Given that the numbers to add is 45 and 29. Now we will perform a partial sum of those numbers,
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-4-Fluently-Add-Within-100-29-1

Question 8.
28 + 39
Envision Math Common Core 2nd Grade Answer Key Topic 4 Fluently Add Within 100 30
Answer:
The sum of the given numbers is 67.

Explanation:
Given that the numbers to add is 28 and 39. Now we will perform a partial sum of those numbers,
Envision-Math-Common-Core-2nd-Grade-Answer-Key-Topic-4-Fluently-Add-Within-100-30-1

Number Sense Write each missing tens or ones digit.
Question 9.
23 + 1☐ = 37
Answer:
23 + 14 = 37.

Explanation:
To find the missing digit, we will do subtraction
37 – 23  = 14.
Here, the missing digit is 4.

Question 10.
59 = ☐8 + 31
Answer:
59 = 28 + 31.

Explanation:
To find the missing digit, we will do subtraction
59 – 31 = 28
Here, the missing digit is 2.

Problem Solving

Solve each problem. Show your work.
Question 11.
Model 34 students are on the playground. 17 students are in the gym. How many students are there in all?
_________ students
Answer:
The number of students are there in all is 51 students.

Explanation:
Given that 34 students are on the playground and 17 students are in the gym. So the number of students are there in all is 34 + 17 which is 51 students.

Question 12.
Sarah put 8 white roses in a vase. Then she added 7 red roses and 12 yellow roses to the vase. How many roses are in the vase now?
_______ roses
Answer:
The number of roses is in the vase now is 27 roses.

Explanation:
Given that Sarah put 8 white roses in a vase and then she added 7 red roses and 12 yellow roses to the vase. So the number of roses are in the vase now is 8 + 7 + 12 which is 27 roses.

Envision Math Common Core 2nd Grade Answers Topic 4 Fluently Add Within 100 31

Question 13.
Higher Order Thinking Write each missing tens or ones digit. What strategy did you use?
12 + 3☐ = 50
24 + 3☐ = 60
35 + 3☐ = 70
Answer:
The missing digits are 8, 6, 5.

Explanation:
To find the missing digit, we will do subtraction
50 – 12 = 38.
Here, the missing digit is 8.
To find the missing digit, we will do subtraction
60 – 24 = 36.
Here, the missing digit is 6.
To find the missing digit, we will do subtraction
70 – 35 = 35
Here, the missing digit is 5.

Question 14.
Assessment Practice which is the sum of 28 + 36? Use partial sums to solve.
A. 8
B. 12
C. 54
D. 64
Answer:
The sum of 28 + 36 is 64.

Explanation:
The partial sum of 28 + 36 is
28
+ 36
——————–
20 + 30 = 50
8 + 6     = 14
——————–
64

Lesson 4.4 Add Using Mental Math and Partial Sums

Solve & Share
Add 46 + 26. Explain how you solved the problem.

I can … add numbers using place value and partial sums.

Visual Learning Bridge
Envision Math Common Core 2nd Grade Answers Topic 4 Fluently Add Within 100 32

Convince Me! Roger found 54 + 27. His sum was 71. Is he correct? Why or why not? Use partial sums to check.

Answer:
Roger is not correct.

Explanation:
Given that Roger found 54 + 27. His sum was 71, let’s check using the partial sum
54
+ 27
——————–
50 + 20 = 70
4 + 7     = 11
——————–
81
Roger is not correct, because the sum of 54 + 27 is 81.

Guided Practice

Write the addition problem. Use partial sums. Add any way you choose. Show your work.
Question 1.
34 + 17
Envision Math Common Core 2nd Grade Answers Topic 4 Fluently Add Within 100 33
Answer:
The sum of 34 + 17 is 51.

Explanation:
The partial sum of 34 + 17 is 51.
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-4-Fluently-Add-Within-100-33-1

Question 2.
52 + 31
Envision Math Common Core 2nd Grade Answers Topic 4 Fluently Add Within 100 33
Answer:
The sum of 52 + 31 is 83.

Explanation:
The partial sum of 52 + 31 is 83.
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-4-Fluently-Add-Within-100-33-2

Question 3.
35 + 26
Envision Math Common Core 2nd Grade Answers Topic 4 Fluently Add Within 100 33
Answer:
The sum of 35 + 26 is 61.

Explanation:
The partial sum of 35 + 26 is 61.
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-4-Fluently-Add-Within-100-33-3

Independent Practice

Write the addition problem. Use partial sums. Add any way you choose. Show your work.
Question 4.
15 + 28
Envision Math Common Core 2nd Grade Answers Topic 4 Fluently Add Within 100 33
Answer:
The sum of 15 + 28 is 43.

Explanation:
The partial sum of 15 + 28 is 43.
Envision-Math-Common-4Core-2nd-Grade-Answers-Topic-4-Fluently-Add-Within-100-33-4

Question 5.
29 + 20
Envision Math Common Core 2nd Grade Answers Topic 4 Fluently Add Within 100 33
Answer:
The sum of 29 + 20 is 49.

Explanation:
The partial sum of 29 + 20 is 49.
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-4-Fluently-Add-Within-100-33-5

Question 6.
63 + 29
Envision Math Common Core 2nd Grade Answers Topic 4 Fluently Add Within 100 33
Answer:
The sum of 63 + 29 is 92.

Explanation:
The partial sum of 63 + 29 is 92.
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-4-Fluently-Add-Within-100-33-6

Question 7.
37 + 48
Envision Math Common Core 2nd Grade Answers Topic 4 Fluently Add Within 100 33
Answer:
The sum of 37 + 48 is 85.

Explanation:
The partial sum of 37 + 48 is 85.
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-4-Fluently-Add-Within-100-33-7

Add any way you choose. Show your work.
Question 8.
67 + 17 = ________
Answer:
The sum of 67 + 17 is 84.

Explanation:
The partial sum of 67 + 17 is 84.
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-4-Fluently-Add-Within-100-33-8

Question 9.
15 + 18 = ________
Answer:
The sum of 15 + 18 is 33.

Explanation:
The partial sum of 15 + 18 is 33.
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-4-Fluently-Add-Within-100-33-9

Question 10.
43 + 49 = ________
Answer:
The sum of 43 + 49 is 92.

Explanation:
The partial sum of 43 + 49 is 92.
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-4-Fluently-Add-Within-100-33-10

Question 11.
62 + 28 = ________
Answer:
The sum of 62 + 28 is 90.

Explanation:
The partial sum of 62 + 28 is 90.
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-4-Fluently-Add-Within-100-33-11

Number Sense Write the missing ones or tens digits.
Question 12.
27 + 2☐ = 50
Answer:
The missing digit is 3.

Explanation:
To find the missing digit, we will do subtraction
50 – 27 = 23.
Here, the missing digit is 3.

Question 13.
3☐ + 16 = 48
Answer:
The missing digit is 2.

Explanation:
To find the missing digit, we will do subtraction
48 – 16 = 32.
Here, the missing digit is 2.

Question 14.
☐4 + 49 = 93
Answer:
The missing digit is 4.

Explanation:
To find the missing digit, we will do subtraction
93 – 49 = 44.
Here, the missing digit is 4.

Problem Solving

Solve each problem. Show your work. Use drawings, if needed.
Question 15.
Amir plants 25 trees. Juan plants 27 trees. How many trees do they plant in all?
________ trees
Answer:
The total number of trees do they plant in all is 52 trees.

Explanation:
Given that Amir plants 25 trees and Juan plant 27 trees, so the total number of trees do they plant in all is 25 + 27 which is 52 trees.

Question 16.
On Monday, Sasha puts 32 pennies in her bank. On Tuesday, she puts 57 more pennies in her bank. How many pennies does she put in her bank on both days?
________ pennies
Answer:
The number of pennies does she puts in her bank on both days is 89 pennies.

Explanation:
Given that, on Monday, Sasha puts 32 pennies in her bank, and on Tuesday, she puts 57 more pennies in her bank. So the number of pennies does she puts in her bank on both days is 32 + 57 which is 89 pennies.

Question 17.
Higher Order Thinking Write an addition story using 2 two-digit numbers. Then solve the problem for your story.
Answer:
The number of toffies is there in all is 86 toffies.

Explanation:
There are 60 toffies in a jar. Harry adds 26 toffies more. How many toffies are there in all?

Answer:
Given that there are 60 toffies in a jar and Harry adds 26 toffies more. So the number of toffies are there in all is 60 +26 which is 86 toffies.

Question 18.
Assessment Practice Find 52 + 39 using partial sums. Show how you solved the problem.
52 + 39 = ________
Answer:
The sum of 52 + 39 is 91.

Explanation:
The partial sum of 52 + 39 is 91
52
+ 39
——————–
50 + 30 = 80
2 + 9     = 11
——————–
91

Lesson 4.5 Break Apart Numbers and Add Using Mental Math

Solve & Share
Monica has 24 crayons. Paul has 64 crayons. How many crayons do they have in all? Use place-value blocks or draw a picture to explain your work.

I can … add within 100 using place value strategies.
Envision Math Common Core 2nd Grade Answers Topic 4 Fluently Add Within 100 34

Answer:
The number of crayons do they have is 88 crayons.

Explanation:
Given that Monica has 24 crayons and Paul has 64 crayons. So the number of crayons do they have is 64 + 24 which is 88 crayons.

Visual Learning Bridge
Envision Math Common Core 2nd Grade Answers Topic 4 Fluently Add Within 100 35

Convince Me! Explain one way you can break apart numbers to find 14 + 32.

Guided Practice

Find each sum using mental math. Draw pictures of blocks if needed.
Question 1.
Envision Math Common Core 2nd Grade Answers Topic 4 Fluently Add Within 100 36
Answer:
The sum of 17 + 52 is 69.

Explanation:
The sum of 17 + 52 is
17 + (50 + 2)
= (17 + 50) +2
= 67 + 2
= 69.

Question 2.
Envision Math Common Core 2nd Grade Answers Topic 4 Fluently Add Within 100 37
Answer:
The sum of 69 + 23 is 92.

Explanation:
The sum of 69 + 23 is
69 + (20 + 3)
= (69 + 20) +3
= 89 + 3
= 92.
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-4-Fluently-Add-Within-100-37-1

Independent Practice

Find each sum using mental math. Draw pictures of blocks if needed.
Question 3.
Envision Math Common Core 2nd Grade Answers Topic 4 Fluently Add Within 100 38
Answer:
The sum of 23 + 26 is 49.

Explanation:
The sum of 23 + 26 is
23 + (20 + 6)
= (23 + 20) +6
= 43 + 6
= 49.
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-4-Fluently-Add-Within-100-38-1

Question 4.
Envision Math Common Core 2nd Grade Answers Topic 4 Fluently Add Within 100 39
Answer:
The sum of 9 + 42 is 51.

Explanation:
The sum of 9 + 42 is
9 + (40 + 2)
= (9 + 40) + 2
= 49 + 2
= 51.
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-4-Fluently-Add-Within-100-39-1

Question 5.
Envision Math Common Core 2nd Grade Answers Topic 4 Fluently Add Within 100 40
Answer:
The sum of 51 + 16 is 67.

Explanation:
The sum of 51 + 16 is
51 + (10 + 6)
= (51 + 10) + 6
= 61 + 6
= 67.
Envision-Math-Common-Core-2nd-Grade-Answers-Topic-4-Fluently-Add-Within-100-40-1

Question 6.
56 + 15 = _______
Answer:
The sum of 56 + 15 is 71.

Explanation:
The sum of 56 + 15 is
56 + (10 + 5)
= (56 + 10) + 5
= 66 + 5
= 71.

Question 7.
_______ = 76 + 18
Answer:
The sum of 76 + 18 is 94.

Explanation:
The sum of 76 + 18 is
76 + (10 + 8)
= (76 + 10) + 8
= 86 + 8
= 94.

Question 8.
33 + 49 = ________
Answer:
The sum of 33 + 49 is 82.

Explanation:
The sum of 33 + 49 is
33 + (40 + 9)
= (33 + 40) + 9
= 73 + 9
= 82.

Add tens and ones to solve.
Question 9.
Algebra One number makes both equations true. Find the missing number.
17 + ☐ = 28
☐ + 28 = 39
Answer:
The missing digit is 11.

Explanation:
To find the missing digit, we will do subtraction
28 – 17 = 11.
Here, the missing digit is 11.
To find the missing digit, we will do subtraction
39 – 28 = 11.
Here, the missing digit is 11.

Problem Solving

Generalize Solve each problem mentally. Show your work. Think about the steps you do every time you break apart numbers to add.
Question 10.
Billy puts 34 skateboard wheels in a pile. He puts 34 more wheels in another pile. How many wheels does Billy have in all?
_________ wheels
Answer:
The number of wheels does Billy has in all is 68 wheels.

Explanation:
Given that Billy puts 34 skateboard wheels in a pile and he puts 34 more wheels in another pile. So the number of wheels does Billy has in all is 34 + 34 which is 68 wheels.

Question 11.
enVision® STEM A new office and house were built in a town. 24 windows are needed for the office. 18 windows are needed for the house. How many windows are needed in all?
_________ windows
Answer:
The number of windows is 42 windows.

Explanation:
Given that a new office and house were built in a town with 24 windows are needed for the office and 18 windows are needed for the house. So the number of windows 24 + 18 which 42 windows.

Question 12.
Higher Order Thinking Write a story problem about 14 + 41. Then solve the problem.
14 + 41 = ________
Answer:

Question 13.
Assessment Practice Use mental math to find 15 + 12. Explain why the strategy works.
Answer:
The sum of 15 + 12 is 27.

Explanation:
The sum of 15 + 12 is
15 + (10 + 2)
= (15 + 10) + 2
= 25 + 2
= 27.

Lesson 4.6 Add More than Two 2-Digit Numbers

Solve & Share
12 + 34 + 28 = ?
Tom says he can find the sum by adding 28 and 12 first. He says he can add 34 to that sum to find the total.
Do you agree? Use pictures, words, and numbers to make a math argument. Then solve the problem. Show your work.

I can … add three or four 2-digit numbers.
Envision Math Common Core 2nd Grade Answers Topic 4 Fluently Add Within 100 41

Visual Learning Bridge
Envision Math Common Core 2nd Grade Answers Topic 4 Fluently Add Within 100 42

Convince Me! Look above. Why do you think the order of the addends changed? Why do you think 24 and 16 were added together?

Guided Practice

Add. Use any strategy. Show your work.
Question 1.
18+ 15 + 12 = _______
Envision Math Common Core 2nd Grade Answers Topic 4 Fluently Add Within 100 43

Question 2.
11 + 14 + 39 = ________
Answer:
11 + 14 + 39 = 64.

Explanation:
Given that 11 + 14 + 39
= 25 + 39
= 64.

Question 3.
21 + 14 + 41 + 22 = ________
Answer:
21 + 14 + 41 + 22 = 98.

Explanation:
Given that 21 + 14 + 41 + 22
= 35 + 63
= 98.

Question 4.
21 + 15 + 32 + 25 = ________
Answer:
21 + 15 + 32 + 25 = 93.

Explanation:
Given that 21 + 15 + 32 + 25
= 36 + 57
= 93.

Independent Practice

Add. Use any strategy. Show your work.
Question 5.
27 + 21 + 13 = ________
Answer:
27 + 21 + 13 = 61.

Explanation:
Given that 27 + 21 + 13
= 48 +13
= 61.

Question 6.
16 + 32 + 28 = ________
Answer:
16 + 32 + 28 = 76.

Explanation:
Given that 16 + 32 + 28
= 48 + 28
= 76.

Question 7.
32 + 14 + 42 = ________
Answer:
32 + 14 + 42 = 88.

Explanation:
Given that 32 + 14 + 42
= 46 + 42
= 88.

Question 8.
25 + 17 + 24 + 15 = ________
Answer:
25 + 17 + 24 + 15 = 81.

Explanation:
Given that 25 + 17 + 24 + 15
= 42 + 39
= 81.

Question 9.
32 + 16 + 18 + 31 = ________
Answer:
32 + 16 + 18 + 31 = 97.

Explanation:
Given that 32 + 16 + 18 + 31
= 48 + 49
= 97.

Question 10.
37 + 11 + 13 + 38 = ________
Answer:
37 + 11 + 13 + 38 = 99.

Explanation:
Given that 37 + 11 + 13 + 38
= 48 + 51
= 99.

Algebra Find the missing numbers.
Question 11.
8 + 3 + Envision Math Common Core 2nd Grade Answers Topic 4 Fluently Add Within 100 44 + 2 = 18
Answer:
The missing digit is 5.

Explanation:
Let the missing number be X, 8 + 3 + X + 2 = 18 which is 13 + X = 18.
To find the missing digit, we will do subtraction
X = 18 – 13
= 5.
Here, the missing digit is 5.

Question 12.
5 + Envision Math Common Core 2nd Grade Answers Topic 4 Fluently Add Within 100 44 + 6 + 5 = 19
Answer:
The missing digit is 3.

Explanation:
Let the missing number be X, 5 + X + 6 + 5 = 19 which is 16 + X = 19.
To find the missing digit, we will do subtraction
X = 19 – 16
= 3.
Here, the missing digit is 3.

Question 13.
7 + 27 + 23 + Envision Math Common Core 2nd Grade Answers Topic 4 Fluently Add Within 100 44 = 61
Answer:
The missing digit is 4.

Explanation:
Let the missing number be X, 7 + 27 + 23 + X = 61 which is 57 + X = 61.
To find the missing digit, we will do subtraction
X = 61 – 57
= 4.
Here, the missing digit is 4.

Question 14.
Envision Math Common Core 2nd Grade Answers Topic 4 Fluently Add Within 100 44 + 24 + 18+ 4 = 52
Answer:
The missing digit is 6.

Explanation:
Let the missing number be X, X + 24 + 18 + 4 = 52 which is 46 + X = 52.
To find the missing digit, we will do subtraction
X = 52 – 46
= 6.
Here, the missing digit is 6.

Problem Solving

Reasoning Solve each problem. Show your work.
Question 15.
28 trucks are blue. 32 trucks are yellow. 17 trucks are green. Il trucks are pink. How many trucks are there in all?
Envision Math Common Core 2nd Grade Answers Topic 4 Fluently Add Within 100 45
_______ trucks
Answer:
The total number of trucks is 88 trucks.

Explanation:
Given that there are 28 blue trucks, 32 yellow trucks and 17 green trucks, and 11 pink trucks. So the total number of trucks are 28 + 32 + 17 + 11 which is 88 trucks.

Question 16.
Joel won 19 tickets in March, 24 tickets in April, 23 tickets in May, and 16 tickets in June. How many tickets does Joel have in all?
_________ tickets
Answer:
The number of tickets Joel has in all is 82 tickets.

Explanation:
Given that Joel won 19 tickets in March, 24 tickets in April, 23 tickets in May, and 16 tickets in June. So the number of tickets Joel have in all is 19 + 24 + 23 + 16 =  82 tickets.

Question 17.
Higher Order Thinking Henry is adding the numbers 24, 18, and 36. He makes a ten to add. Which ones digits does Henry add first? Explain.
Envision Math Common Core Grade 2 Answer Key Topic 4 Fluently Add Within 100 46
Answer:

Question 18.
Assessment Practice Find the sum. Use any strategy. Show your work.
25 + 16 + 15 + 38 = _________
Answer:
The sum of 25 + 16 + 15 + 38 = 94.

Explanation:
Given that 25 + 16 + 15 + 38
= 41 + 53
= 94.

Lesson 4.7 Practice Adding Using Strategies

Solve & Share
Maria has 39 stickers. Sally has 28 stickers. They found 14 more stickers. How many stickers do they have in all? Solve. Use any strategy. Explain how you found the answer.
I can … use mental math, strategies, and models to add two, three, or four numbers.
Envision Math Common Core Grade 2 Answer Key Topic 4 Fluently Add Within 100 47

Visual Learning Bridge
Envision Math Common Core Grade 2 Answer Key Topic 4 Fluently Add Within 100 48

Convince Me! Find the sum of 14 + 28 +33 + 22. Explain.

Guided Practice

Add. Use any strategy. Show your work.
Question 1.
18 + 43 + 12 = _______
Envision Math Common Core Grade 2 Answer Key Topic 4 Fluently Add Within 100 49
Answer:

Question 2.
29 + 47 = _______
Answer:
The sum of 29 + 47 = 76.

Explanation:
Given that 29 + 47 which is
20 + 40 = 60
9 + 7 = 16
60 + 16 = 76.

Question 3.
9 + 34 + 21 = _______
Answer:
The sum of 9 + 34 + 21 is 64.

Explanation:
Given that 9 + 34 + 21 which is
30 + 20 = 50
9 + 4 + 1 = 14
50 + 14 = 64.

Question 4.
33 + 27 + 18 + 13 = _______
Answer:
The sum of 33 + 27 + 18 + 13 = 91.

Explanation:
Given that 33 + 27 + 18 + 13 which is
30 + 20 + 10 + 10 = 70
3 + 7 + 8 + 3 = 21
70 + 21 = 91.

Independent Practice

Add. Use any strategy. Show your work.
Question 5.
31 + 5 + 29 = _______
Answer:
The sum of 31 + 5 + 29 = 65.

Explanation:
Given that 31 + 5 + 29 which is
30 + 20 = 50
1 + 5 + 9 =15
50 + 15 = 65.

Question 6.
20 + 18 + 16 = _______
Answer:
The sum of 20 + 18 + 16 = 54.

Explanation:
Given that 20 + 18 + 16 which is
20 + 10 + 10 = 40
8 + 6 = 14
40 + 14 = 54.

Question 7.
8 + 17 = _______
Answer:
The sum of 8 + 17 is 25.

Explanation:
Given that 8 + 17
8 + 7 = 15
10 + 15 = 25.

Add. Use partial sums. Think about compatible numbers.
Question 8.
Envision Math Common Core Grade 2 Answer Key Topic 4 Fluently Add Within 100 50
Answer:
The sum of 25 + 13 + 12 + 5 = 55.

Explanation:
Given that 25 + 13 + 12 + 5 which is
20 + 10 + 10 = 40
5 + 3 + 2 + 5 = 15
40 + 15 = 55.

Question 9.
Envision Math Common Core Grade 2 Answer Key Topic 4 Fluently Add Within 100 51
Answer:
The sum of 9 + 29 + 5 + 35 = 70.

Explanation:
The sum of 9 + 29 + 5 + 35 which is
20 + 30 = 50
9 + 9 + 5 + 5 = 28
50 + 28 = 78.

Question 10.
Envision Math Common Core Grade 2 Answer Key Topic 4 Fluently Add Within 100 52
Answer:
The sum of 18 + 24 + 42 + 6 is 90.

Explanation:
The sum of 18 + 24 + 42 + 6 which is
10 + 20 + 40 = 70
8 + 4 + 2 + 6 = 20
70 + 20 = 90.

Question 11.
Envision Math Common Core Grade 2 Answer Key Topic 4 Fluently Add Within 100 53
Answer:
The sum of 27 + 15 + 33 + 24 = 99.

Explanation:
The sum of 27 + 15 + 33 + 24 is
20 + 10 + 30 + 20 = 80
7 + 5 + 3 + 4 = 19
80 + 19 = 99.

Question 12.
Envision Math Common Core Grade 2 Answer Key Topic 4 Fluently Add Within 100 54
Answer:
The sum of 13 + 7 + 20 + 55 = 95.

Explanation:
The sum of 13 + 7 + 20 + 55 is
10 + 20 + 50 = 80
3 + 7 + 5 = 15
80 + 15 = 95.

Number Sense Solve each problem. In which order did you add the numbers? Explain.
Question 13.
22 + 17 + 8 + 3 = ________
Answer:
The sum of 22 + 17 + 8 + 3 is 50.

Explanation:
The sum of 22 + 17 + 8 + 3 is
20 + 10 = 30
2 + 7 + 8 + 3 = 20
30 + 20 = 50.

Question 14.
5 + 12 + 15 + 3 = ________
Answer:
The sum of 5 + 12 + 15 + 3 = 35.

Explanation:
The sum of 5 + 12 + 15 + 3 is
10 + 10 = 20
5 + 2 + 5 + 3 = 15
20 + 15 = 35.

Problem Solving

Solve each problem. Show your work.
Question 15.
Model Kim has 38 seashells. Mike has 27 seashells. Use partial sums to find how many shells they have in all. Then check your answer by adding another way.
__________ seashells
Answer:
The number of shells they have in all is 65 seashells.

Explanation:
Given that Kim has 38 seashells and Mike has 27 seashells. So the number of shells they have in all is 38 + 27 which is
30 + 20 = 50
8 + 7 = 15.
50 + 15 = 65.

Question 16.
en Vision® STEM Fossils form slowly over millions of years. Many fossils come from the sea. Kyle has 9 fossils, Jorie has 12 fossils, Leah has 6 fossils, and Joshua has 8 fossils. How many fossils do they have in all?
Envision Math Common Core Grade 2 Answer Key Topic 4 Fluently Add Within 100 55
__________ fossils
Answer:
The total number of fossils do they have in all is 35 fossils.

Explanation:
Given that Kyle has 9 fossils, Jorie has 12 fossils, Leah has 6 fossils, and Joshua has 8 fossils. So the total number of fossils do they have in all is 9 + 12 + 6 + 8 which is
9 + 6 + 8 + 2 = 25
10 + 25 = 35.

Question 17.
Higher Order Thinking Find the sum of 42 + 13 + 18 + 7 = _________ . Explain why your strategy works.
Answer:
The sum of 42 + 13 + 18 + 7 is 80.

Explanation:
The sum of 42 + 13 + 18 + 7 is
40 + 10 + 10 = 60
2 + 3 + 8 + 7 = 20
60 + 20 = 80.

Question 18.
Assessment Practice Find the sum of 17 + 29 + 46. Use any strategy. Show your work.
17 + 29 + 46 = __________
Answer:
The sum of 17 + 29 + 46 = 92.

Explanation:
The sum of 17 + 29 + 46 is
10 + 20 + 40 = 70
7 + 9 + 6 = 22
22 + 70 = 92.

Lesson 4.8 Solve One-Step and Two-Step Problems

Solve & Share
The second graders take a trip to a nature center. The Green Class sees 23 animals. The Blue Class sees 14 animals. The Yellow Class sees 32 animals. How many animals do they see in all?
Solve using drawings, models, or an equation. Be prepared to explain your work.

I can … use drawings, models, and equations to solve one- and two-step problems.
Envision Math Common Core Grade 2 Answer Key Topic 4 Fluently Add Within 100 56
_________ animals

Answer:
The total number of animals do they see all is 69 animals.

Explanation:
Given that the second graders take a trip to a nature center. The Green Class sees 23 animals and the Blue Class sees 14 animals and the Yellow Class sees 32 animals. So the total number of animals do they see all is 23 + 14 + 32 which is
= 37 + 32
= 69 animals.

Visual Learning Bridge
Envision Math Common Core Grade 2 Answer Key Topic 4 Fluently Add Within 100 57

Convince Me! What is a different way you can use mental math to find 36 + ? = 53?

Answer:
36 + 17 = 53.

Explanation:
The different way we can use mental math is to find 36 + ? = 53 is first we will add 10 to the number 36 then we will get 36 + 10 which is 46 and here the result is 53, so we need to add 7 more. So it will be 46 + 7 which is 53.

Guided Practice

Use the bar diagram and mental math to solve each problem. Then check your work.
Question 1.
Bruce buys 18 eggs. He uses 10 of them for baking. Then he buys 36 more eggs. How many eggs does Bruce have now?
Check:
Envision Math Common Core Grade 2 Answer Key Topic 4 Fluently Add Within 100 58
________ eggs
Answer:
The total number of eggs is 44 eggs.

Explanation:
Given that Bruce buys 18 eggs and he uses 10 of them for baking, so the number of eggs will be 18 – 10 which is 8 eggs. And then he buys 36 more eggs. So the number of eggs will be 8 + 36 which is 44 eggs.

Independent Practice

Use the bar diagram(s) and mental math to solve each problem. Then check your work.
Question 2.
Ella has 34 more buttons than Julio. Julio has 49 buttons. How many buttons does Ella have?
Check
Envision Math Common Core Grade 2 Answer Key Topic 4 Fluently Add Within 100 59
________ buttons
Answer:
The number of buttons does Ella has now is 83 buttons.

Explanation:
Given that Ella has 34 more buttons than Julio and Julio has 49 buttons. So the number of buttons does Ella has now is 49 + 34 which is 83 buttons.
Envision-Math-Common-Core-Grade-2-Answer-Key-Topic-4-Fluently-Add-Within-100-59-1

Question 3.
20 students are on the bus. Then 10 students get off the bus. Next, 15 students get on the bus. How many students are on the bus now?
Check:
Envision Math Common Core Grade 2 Answer Key Topic 4 Fluently Add Within 100 60
________ students
Answer:
The total number of students will be 25 students.

Explanation:
Given that there are 20 students are on the bus and then 10 students get off the bus. So the number of students will be 20 – 10 which is 10 students. And then 15 students get on the bus, so the number of students now is 10 + 15  which is 25 students. So the total number of students will be 25 students.
Envision-Math-Common-Core-Grade-2-Answer-Key-Topic-4-Fluently-Add-Within-100-60-1

Question 4.
Wendy has 14 more crayons than Oscar. Oscar has 54 crayons. How many crayons does Wendy have?
Envision Math Common Core Grade 2 Answer Key Topic 4 Fluently Add Within 100 61
_________ crayons
Answer:
The number of crayons Wendy has is 68 crayons.

Explanation:
Given that Wendy has 14 more crayons than Oscar and Oscar has 54 crayons. So the number of crayons Wendy has is 54 + 14 which is 68 crayons.
Envision-Math-Common-Core-Grade-2-Answer-Key-Topic-4-Fluently-Add-Within-100-61-1

Problem Solving

Solve each problem. Show your work.
Question 5.
Make Sense Mariah has 17 figs. Kendra has 20 more figs than Mariah. Toby has 33 more figs than Kendra. How many figs do Kendra and Toby each have?
Step 1:
How many figs does Kendra have?
________ Envision Math Common Core Grade 2 Answer Key Topic 4 Fluently Add Within 100 62 _______ = ________ figs
Step 2: How many figs does Toby have?
________ Envision Math Common Core Grade 2 Answer Key Topic 4 Fluently Add Within 100 62 _______ = ________ figs
Solve one step at a time.
Answer:
Kendra has 17 + 20 = 37 figs.
Toby has 37 + 33 = 70 figs.

Explanation:
Given that Mariah has 17 figs and Kendra has 20 more figs than Mariah, so the number of figs does Kendra has now is 17 + 20 which is 37 figs.
Toby has 33 more figs than Kendra, so the number of figs does Toby has now is 37 + 33 which is 70 figs.

Question 6.
Higher Order Thinking 8 girls and some boys are in the pool. In all, 17 children are in the pool. Then some more boys jump in the pool. Now there are 13 boys in the pool. How many more boys jumped in the pool?
Step 1:
________ Envision Math Common Core Grade 2 Answer Key Topic 4 Fluently Add Within 100 62 _______ = ________
Step 2:
________ Envision Math Common Core Grade 2 Answer Key Topic 4 Fluently Add Within 100 62 _______ = ________
_________ more boys jumped in the pool
Answer:
4 more boys jumped in the pool.

Explanation:
Given that 8 girls and some boys are in the pool. In all, 17 children are in the pool, so the number of boys in the pool is 17 – 8 which is 9 boys. As some boys jump into the pool and the boys in the pool are 13. So the number of boys who jumped in the pool is 13 – 9 which is 4 boys.

Question 7.
Assessment Practice The soccer coach has 18 shirts. She gives 9 of the shirts to some of her players. Then she gets 11 more shirts. How many shirts does the coach have left?
Show how you can solve the problem in two steps.
Step 1:
Step 2:
The coach has ________ shirts left.
Answer:
The coach has 20 shirts left.

Explanation:
Given that the soccer coach has 18 shirts and she gives 9 of the shirts to some of her players, so the number of shirts does coach had is 18 – 9 which is 9 shirts. And then gets 11 more shirts, so the total number of shirts does the coach has left is 9 + 11 which is 20 shirts.

Lesson 4.9 Problem Solving

Model with Math
Solve & Share
Kim puts 25 toys into an empty toy box. Then she puts 17 more toys in the toy box. How many toys are in the box in all?
Use a model to show the problem. Be ready to explain how your model helps you solve the problem.

I can … make models to help solve math problems.
Envision Math Common Core Grade 2 Answer Key Topic 4 Fluently Add Within 100 63

Answer:
The total number of toys in the box is 42 toys.

Explanation:
Given that Kim puts 25 toys into an empty toy box and then she puts 17 more toys in the toy box. So the total number of toys in the box is 25 + 17 which is 42 toys.
Envision-Math-Common-Core-Grade-2-Answer-Key-Topic-4-Fluently-Add-Within-100-63-1

Thinking Habits
Can I write an equation or use a drawing, diagram, table, graph, or objects to show the problem?

Visual Learning Bridge
Envision Math Common Core Grade 2 Answer Key Topic 4 Fluently Add Within 100 64

Convince Me! How does drawing a bar diagram or writing an equation model a problem? Is there another way to model the problem?

Answer:
Here, both the bar diagram and writing an equation model for a problem works.

Guided Practice

Complete the bar diagram. Write an equation to model the problem. Then solve.
Question 1.
Flora has 24 books about birds. She has 18 books about bugs. How many books is that?
Envision Math Common Core Grade 2 Answer Key Topic 4 Fluently Add Within 100 65

Answer:
The number of books is 42 books.

Explanation:
Given that Flora has 24 books about birds and she has 18 books about bugs. So the number of books is 24 + 18 which is 42 books.

Question 2.
Barb saw 14 cars on Smith Street. She saw 8 cars on Alfred Street. How many more cars did Barb see on Smith Street?
Envision Math Common Core Grade 2 Answer Key Topic 4 Fluently Add Within 100 66
_______ Envision Math Common Core Grade 2 Answer Key Topic 4 Fluently Add Within 100 62 _______ = ________ cars
Answer:
The number of cars did Barb see on Smith Street is 22 cars.

Explanation:
Given that Barb saw 14 cars on Smith Street and she saw 8 cars on Alfred Street. So the number of cars did Barb see on Smith Street is 14 + 8 which is 22 cars.
Envision-Math-Common-Core-Grade-2-Answer-Key-Topic-4-Fluently-Add-Within-100-66-1

Independent Practice

Make a model to show each problem. Then use the model to solve. Show your work.
Question 3.
Avi takes 16 pictures. Then he takes 17 more pictures. How many pictures does Avi take?
Envision Math Common Core Grade 2 Answer Key Topic 4 Fluently Add Within 100 67
Answer:
The number of pictures does Avi take is 33 pictures.

Explanation:
Given that Avi takes 16 pictures and then he takes 17 more pictures. So the number of pictures does Avi take is 16 + 17 which is 33 pictures.

Question 4.
Tina picks 55 blueberries. Next, Tina eats 6 of these blueberries. Then she picks 27 more. How many blueberries does she have now?
Answer:
The number of blueberries does she have now is 76 blueberries.

Explanation:
Given that Tina picks 55 blueberries and Tina eats 6 of these blueberries, so the number of blueberries is 55 – 6 which is 49 blueberries. Now she picks 27 more, so the number of blueberries does she have now is 49 + 27 which is 76 blueberries.

Question 5.
Raj finds 47 acorns in his front yard. He finds 29 acorns in his back yard. How many acorns does Raj find in all?
Answer:
The number of acorns does Raj finds in all is 76 acorns.

Explanation:
Given that Raj finds 47 acorns in his front yard and he finds 29 acorns in his back yard. So the number of acorns does Raj finds in all is 47 + 29 which is 76 acorns.

Problem Solving

Performance Task
African Safari The Santos family is on an African safari. The chart at the right shows the number of animals they see. How many animals do they see?
Envision Math Common Core Grade 2 Answer Key Topic 4 Fluently Add Within 100 68

Question 6.
Make Sense What do you know? What are you asked to find?
Answer:
Here, we know that how many animals they saw of each type of animal and we need to find the total.

Question 7.
Model Make a model to help you find the number of animals they see. Be ready to explain why you chose the model you did.
Answer:
The number of animals they see is 51 animals.

Explanation:
Given that there are 15 giraffes, 9 elephants, 16 lions and 11 zebras. So the number of animals they see are 15 + 9 + 16 + 11
= 24 + 27
= 51.

Question 8.
Model What other model could you use to show the problem? Make another model. Explain which model you think is better.
Answer:

Topic 4 Fluency Practice Activity

Point & Tally
Find a partner. Get paper and a pencil. Each partner chooses a different color: light blue or dark blue.
Partner I and Partner 2 each point to a black number at the same time. Both partners add those numbers.
If the answer is on your color, you get a tally mark. Work until one partner gets twelve tally marks.

I can … add within 20.
Envision Math Common Core Grade 2 Answer Key Topic 4 Fluently Add Within 100 69

Topic 4 Vocabulary Review

Understand Vocabulary
Word List

  • addends
  • compatible numbers
  • ones
  • partial sum
  • regroup
  • sum
  • tens

Use the problem at the right. Write partial sum or sum for each.
Envision Math Common Core Grade 2 Answer Key Topic 4 Fluently Add Within 100 70
Question 1.
70 is a _________ .
Answer:
70 is a partial sum.

Explanation:
Here, the number 70 is a partial sum, because partial sum is just a sum of part of sequence.

Question 2.
17 is a ___________.
Answer:
17 is a partial sum.

Explanation:
Here, the number 17 is a partial sum, because partial sum is just a sum of part of sequence.

Question 3.
87 is the __________.
Answer:
87 is a sum.

Explanation:
Here, the number 87 is a sum, because it is the result of the addition.

Question 4.
Use the ones column in the problem at the right. Which compatible numbers can you add to make a ten two different ways?
Envision Math Common Core Grade 2 Answers Topic 4 Fluently Add Within 100 71
Write two different equations.
Answer:
8 + 2 = 10,
6 + 4 = 10.

Explanation:
The two different equations which are compatible numbers can we add to make a ten is
8 + 2 = 10,
6 + 4 = 10.

Use Vocabulary in Writing
Question 5.
Solve 27 + 35 by breaking apart both addends. Tell how you solved the problem. Use terms from the Word List.
Answer:
27 + 35 = 65.

Explanation:
Here, we have added the ones and then we will regroup and added to find the sum.
27 + 35 = 65.

Topic 4 Reteaching

Set A

Find 55 + 17. Use place-value blocks. Show the addends. Join the tens and ones. Regroup if needed.
Envision Math Common Core Grade 2 Answers Topic 4 Fluently Add Within 100 72

Add. Use place-value blocks to show your work. Regroup if needed.
Question 1.
36 + 23 = ________
Envision Math Common Core Grade 2 Answers Topic 4 Fluently Add Within 100 73

Answer:
The sum of 36 + 23 is 59 which is 5 tens and 9 ones.

Explanation:
The sum of 36 + 23 is
30 + 20 = 50
6 + 3 = 9
50 + 9 = 59.

Question 2.
19 + 44 = _______
Envision Math Common Core Grade 2 Answers Topic 4 Fluently Add Within 100 74
_______ tens _______ ones
Answer:
The sum of 19 + 44 is  63 which is 6 tens and 3 ones.

Explanation:
The sum of 19 + 44 is
10 + 40 = 50
9 + 4 = 13
50 + 13 = 63.

Set B

Find 24 + 49. Draw place-value blocks to show the addends. Join the tens and ones. Regroup if needed.
Envision Math Common Core Grade 2 Answers Topic 4 Fluently Add Within 100 75

Add. Use place value and draw blocks.
Question 3.
64 + 13 = _______
Answer:
The sum of 64 + 13 is 77 which is 7 tens and 7 ones.

Explanation:
The sum of 64 + 13 is
60 + 10 = 70
4 + 3 = 7
70 + 7 = 77.

Question 4.
27 + 56 = ________
Answer:
The sum of 23 + 56 is 79 which is 7 tens and 9 ones.

Explanation:
The sum of 23 + 56 is
20 + 50 = 70
3 + 6 = 9
70 + 9 = 79.

Set C

You can draw blocks and use partial sums to find 46 + 37.
Envision Math Common Core Grade 2 Answers Topic 4 Fluently Add Within 100 76

Add. Draw place-value blocks and use partial sums.
Question 5.
33 + 57
Drawings:
Envision Math Common Core Grade 2 Answers Topic 4 Fluently Add Within 100 77
Answer:
The partial sum of 33 + 57 is 90.

Explanation:
Given that 33 + 57, the partial sum of 33 + 57 is
Envision-Math-Common-Core-Grade-2-Answers-Topic-4-Fluently-Add-Within-100-77-1

Set D

Find 29 + 63. You can break apart the addends and use partial sums.
Envision Math Common Core Grade 2 Answers Topic 4 Fluently Add Within 100 78

Add. Break apart the addends and use partial sums.
Question 6.
Envision Math Common Core Grade 2 Answers Topic 4 Fluently Add Within 100 79
Answer:
The partial sum of 17 + 77 is 94.

Explanation:
Given that 17 + 77, the partial sum of 17 + 77 is
Envision-Math-Common-Core-Grade-2-Answers-Topic-4-Fluently-Add-Within-100-79-1

Question 7.
Envision Math Common Core Grade 2 Answers Topic 4 Fluently Add Within 100 80
Answer:
The partial sum of 24 + 38 is 62.

Explanation:
Given that 24 + 38, the partial sum of 24 + 38 is
Envision-Math-Common-Core-Grade-2-Answers-Topic-4-Fluently-Add-Within-100-80-1

Set E

Find 32 + 19. Break apart the second addend and add mentally.
Envision Math Common Core Grade 2 Answers Topic 4 Fluently Add Within 100 81

Break apart the second addend to add. Show your work.
Question 8.
Envision Math Common Core Grade 2 Answers Topic 4 Fluently Add Within 100 82
Answer:
The sum of 24 + 55 is 79.

Explanation:
The sum of 24 + 55 is 79.
Envision-Math-Common-Core-Grade-2-Answers-Topic-4-Fluently-Add-Within-100-82-1

Question 9.
Envision Math Common Core Grade 2 Answers Topic 4 Fluently Add Within 100 83
Answer:
The sum of 64 + 27 is 91.

Explanation:
The sum of 64 + 27 is 91.
Envision-Math-Common-Core-Grade-2-Answers-Topic-4-Fluently-Add-Within-100-83-1

Set F

Use partial sums to find 65 + 7 + 13.
Envision Math Common Core Grade 2 Answers Topic 4 Fluently Add Within 100 84

Add using partial sums.
Question 10.
Envision Math Common Core Grade 2 Answers Topic 4 Fluently Add Within 100 85
Answer:
The partial sum is 70.

Explanation:
Given that 22 + 21 + 9 + 18, the partial sum of 22 + 21 + 9 + 18 is
Envision-Math-Common-Core-Grade-2-Answers-Topic-4-Fluently-Add-Within-100-85-1

Question 11.
Envision Math Common Core Grade 2 Answers Topic 4 Fluently Add Within 100 86
Answer:
The partial sum of 41 + 15 + 29 + 10 is 95.

Explanation:
Given that 41 + 15 + 29 + 10, the partial sum of 41 + 15 + 29 + 10 is
Envision-Math-Common-Core-Grade-2-Answers-Topic-4-Fluently-Add-Within-100-86-1

Set G

27 students are eating lunch. More students join them. Now 63 students are eating lunch. How many students joined them?
Write an equation: 27 + ? = 63 Count on to find the missing addend:
Envision Math Common Core Grade 2 Answers Topic 4 Fluently Add Within 100 87
So, 36 students joined them.

Complete the bar diagram, write an equation, and solve.
Question 12.
Lana has 24 crayons. Then she gets some more crayons. Now she has 42 crayons. How many crayons does Lana get?
Envision Math Common Core Grade 2 Answers Topic 4 Fluently Add Within 100 88
Answer:
The number of crayons does Lana gets is 66 crayons.

Explanation:
Given that Lana has 24 crayons and then she gets some more crayons and now she has 42 crayons. So the number of crayons does Lana gets is 24 + 42 which is 66 crayons.
Envision-Math-Common-Core-Grade-2-Answers-Topic-4-Fluently-Add-Within-100-88-1

Set H

Thinking Habits
Model with Math
Can I use a drawing, diagram, table, graph, or objects to show the problem?
Can I write an equation to show the problem?
Envision Math Common Core Grade 2 Answers Topic 4 Fluently Add Within 100 89

Make a model and solve the problem.
Question 13.
Students ride buses to the museum. 28 students ride in Bus A. 27 students ride in Bus B. How many students ride in both buses?
Answer:
The total number of students ride in both buses is 55 students.

Explanation:
Given that 28 students ride in Bus A and 27 students ride in Bus B. So the total number of students ride in both buses is 28 + 27 which is 55 students.

Topic 4 Assessment Practice

Question 1.
Kelly has 46 beads. Her sister gives her 28 more beads. How many beads does Kelly have now?
A. 18
B. 64
C. 22
D. 74
Answer:
The total number of beads does Kelly have now is 74 beads.

Explanation:
Given that Kelly has 46 beads and her sister gives her 28 more beads. So the total number of beads does Kelly have now is 46 + 28 which is 74 beads.

Question 2.
Which are equal to 45 + 38? Choose all that apply.
☐ 40 + 30 + 5+ 8
☐ 93
☐ 45 + 30 + 5 + 3
☐ 40 + 30 + 10
☐ 83
Answer:
Option A and Option E.

Explanation:
Given that 45 + 38, so 45 + 38 is equal to 40 + 30 + 5 + 8 which is 83.

Question 3.
Is the sum equal to 81? Choose Yes or No.
Envision Math Common Core Grade 2 Answers Topic 4 Fluently Add Within 100 90
Answer:
Option B and Option D.

Explanation:
Given that the sum equal to 81, so the addends will be 52  + 29 and 63 + 18 which is 81.
Envision-Math-Common-Core-Grade-2-Answers-Topic-4-Fluently-Add-Within-100-90-1

Question 4.
Find 27 + 44 using partial sums. Show how you solved the problem.
Answer:
The sum of 27 + 44 is 71.

Explanation:
The partial sum of 27 + 44 is
= 27 + 40 + 4
= 67 + 4
= 71.

Question 5.
Which is the sum of 57 + 15?
Envision Math Common Core Grade 2 Answers Topic 4 Fluently Add Within 100 91
A. 82
B. 72
C. 62
D. 42
Answer:
Option B.

Explanation:
The sum of 57 + 15 is 72.

Question 6.
Which are the same amount as 13 + 8 + 7? Choose all that apply.
☐ 20 + 8
☐ 10 + 10 + 8
☐ 18
☐ 28
☐ 20 + 7
Answer:
Option A, Option B and Option D.

Explanation:
The same amount as 13 + 8 + 7 is 20 + 8, 10 + 10 + 8 and 28.

Question 7.
What is the sum of 26 + 53 + 7? Show your work.
26 + 53 + 7 = ________
Answer:
The sum is 86.

Explanation:
The sum of 26 + 53 + 7 is
= 79 + 7
=  86.

Question 8.
Find the sum of 23 and 19. Then subtract 10 from that sum. Show and explain your work.
The answer is __________
Answer:
The answer is 32.

Explanation:
Given that the sum of 23 and 19 is 42 and should subtract 10 from the sum which is 42 – 10 = 32.

Question 9.
A. Find the sum. Use a strategy. Show your work.
25 + 37 + 15 + 8 = __________
Answer:
25 + 37 + 15 + 8 = 85.

Explanation:
The sum of 25 + 37 + 15 + 8 is
= 25 + 60
= 85.

B. Explain how you found the sum and why your strategy works.
Answer:
Here, we will first add ones and got 25 and then we will regroup the 2 tens and then we will add to get the sum of 85.

Question 10.
Ms. Wise has 12 tablets. Then she gets 9 more tablets. Ms. Wise has 20 students in her class. She gives each student one tablet. How many tablets does she have left? Use equations to solve the problem.
________ tablet(s)
Answer:
The number of tablets left with Ms. Wise is 1 tablet.

Explanation:
Given that Ms. Wise has 12 tablets and she gets 9 more tablets, so the total tablets will be 12 + 9 which is 21 tablets. Ms. Wise has 20 students in her class and she gives each student one tablet. So the number of tablets left with Ms. Wise is 21 – 20 which is 1 tablet.

Question 11.
What is the sum of 59 + 33?
Draw place-value blocks and show your work in the blue box at the right.
59 + 33 = _________
Answer:

Question 12.
Each equation has a missing addend. Find it in the number cards. Draw lines to match. Then write the missing addend in the gray box.
Envision Math Common Core Grade 2 Answers Topic 4 Fluently Add Within 100 92
Answer:
The missing addends are 7, 8, 5, 6.

Explanation:
Given that 6 + 14 +– + 3 = 30, so the missing addend is 23 + — = 30 and the missing addend is 30 -23 = 7.
Given that 3 + 32 + 7 +– = 50, so the missing addend is 42+ — = 50 and the missing addend is 50 – 42= 8.
Given that 25 + 25  +– + 5 = 60, so the missing addend is 55 + — = 60 and the missing addend is 60 – 55 = 5.
Given that 5 +– + 15 + 14 = 40, so the missing addend is 34 + — = 40 and the missing addend is 40 – 34 = 6.

Envision-Math-Common-Core-Grade-2-Answers-Topic-4-Fluently-Add-Within-100-92-1

Question 13.
Corey has 17 more marbles than Tony. Tony has 64 marbles. How many marbles does Corey have?
Envision Math Common Core Grade 2 Answers Topic 4 Fluently Add Within 100 93
Use the bar diagram to model and solve the problem. Show your work.
_________ marbles
Answer:
The total number of marbles is 81 marbles.

Explanation:
Given that Corey has 17 more marbles than Tony and Tony has 64 marbles. So the total number of marbles is 17 + 64 which is 81 marbles.

Topic 4 Performance Task

Our Pets
Students draw pictures of their pets. The chart shows the number of pets the students have.
Envision Math Common Core Grade 2 Answers Topic 4 Fluently Add Within 100 94
Question 1.
How many dogs and cats do the students have? Show your work.
_________ dogs and cats
Answer:
&0 students have dogs and cats.

Explanation:
The total number of dogs and cats is 41 + 29 which is 70 students.

Question 2.
How many cats and fish do the students have? Show your work.
__________ cats and fish
Answer:
53 students have cats and fish

Explanation:
The total number of cats and fish is 29 + 24 which is 53 students.

Question 3.
Use partial sums to find how many cats, rabbits, and fish the students have. Be sure to check your work.
Envision Math Common Core Grade 2 Answers Topic 4 Fluently Add Within 100 95
How many cats, rabbits, and fish in all?
__________ cats, rabbits, and fish
Answer:
59 students have cats, rabbits, and fish.

Explanation:
The total number of cats, rabbits, and fish is 29 + 6 + 24 which is 59 students.
Envision-Math-Common-Core-Grade-2-Answers-Topic-4-Fluently-Add-Within-100-95-1

Question 4.
Explain how to use partial sums to add.
Answer:

Question 5.
The students also draw pictures of 10 hamsters, 19 birds, and 5 mice.
Part A
Complete the model to show how to find the total number of hamsters, birds, and mice.
Envision Math Common Core Grade 2 Answers Topic 4 Fluently Add Within 100 96
Answer:

Part B
Complete the equation to show how many hamsters, birds, and mice they draw. Then write the total.
Envision Math Common Core Grade 2 Answers Topic 4 Fluently Add Within 100 97
__________ hamsters, birds, and mice
Answer:

enVision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20

Practice with the help of enVision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 regularly and improve your accuracy in solving questions.

enVision Math Common Core 2nd Grade Answers Key Topic 1 Fluently Add and Subtract Within 20

Essential Question:
What are strategies for finding addition and subtraction facts?
Answer:
The Split and Jump strategies are used for finding Addition and Subtraction.
Explanation:
You can add or subtract the tens separately to the ones (or units).
For example, using the split strategy to add 46 + 23, you would split each number (decompose) into tens and ones: 46 + 23 = 40 + 6 + 20 + 3. rearrange the tens and ones: 40 + 20 + 6 + 3.

Jump Strategy, we can also count by 2s or 10s, or make any “jumps” we want to help us solve a calculation.

 Using a Number Line or Number Chart. This is a very popular and visual way to help students work out subtraction problems.
Jump strategy for addition

Jump strategy for subtraction



Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 1

enVision STEM Project: Material Math
Find Out Collect different types of paper. Talk about the uses of paper. Tell how strong each type of paper is. Tell how the paper feels. Tell if the paper can soak up water.
Journal: Make a Book Show what you find out in a book. In your book, also:

  • Glue samples of paper and tell what you found.
  • Choose a type of paper to make flash cards of addition and subtraction facts.
    Answer:
    Types of Paper:

    • Bond paper. This type of paper is stronger and more durable than the average sheet of paper.
    • Gloss coated paper, it is typically used for flyers and brochures as it has a high shine.
    • Matt coated paper, has a semi-gloss finish, produces high quality prints.
    • Recycled paper, saves landfill space and reduces the amount of pollution in the air. 
    • Silk coated paper, used commonly for leaflets and flyers.
    • Uncoated paper, used for books, letterheads, envelopes, note-pads and a number of other paper products. 

    USES OF PAPER :
    It is a versatile material with many uses, including printing, packaging, decorating, writing, cleaning, filter paper, wallpaper, book endpaper, conservation paper, laminated worktops, toilet tissue, currency and security paper and a number of industrial and construction processes.

    Tell how the paper feels:
    Answer may vary, but paper think poetically
    u can write ur feelings,
    scribble ur anger,
    use me 2 absorb tears.
    Don’t throw me after use but
    when u feel cold burn me
    to feel warm cause I Love you.
    Tell if the paper can soak up water:
    When paper soaked in water it readily absorbs water because it is made of cellulose, which water molecules like to cling to.

    1. Make a List of the Journals Available. …
    2. Determine the Impact of the Journal. …
    3. Make Sure the Journal Scope and Policies match your Needs. …
    4. Check the Journal Requirements and Distribution. …
    5. Collect Information about the Journal’s Peer Review Process. …
    6. Glue samples of paper and tell what you found.
    7. Check the “Instructions for Authors” thoroughly.
      Journal: Make a Book Show what you find out in a book. In your book.
    1. Make Your Own Flash Cards.
    2. Mix Pictures and Words.
    3. Use Mnemonic Devices to Create Mental Connections.
    4. Write Only One Question Per Card.
    5. Break Complex Concepts Into Multiple Questions.Observations of Glue samples of paper.
      PVA Glue. The most versatile adhesive! PVA can be used on a wide range of surfaces: paper, card, fabric, wood, plaster and much more.
      Preparation of flash cards:
      Collect your materials together. This means that you should have your flash cards and textbook ready. Have a good pen, markers, highlighters, and whatever other writing implements you’d like to use.

Question 1.
Circle the symbol for equal
+
=

Answer:

Question 2.
Circle the symbol for minus.

+
=
Answer:

Question 3.
Circle the number that is the whole.
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 2
4 + 2 = 6
Answer:

Subtraction Stories
Question 4.
There are 7 birds on a fence. 2 fly away. How many birds are left?
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 3
_______ birds
Answer:
5 birds
Explanation:
Number of birds on fence = 5
Number of birds fly away = 2
Number of birds left = (7-2) = 5

Addition Stories
Question 5.
Write an equation to solve the problem.
Kate draws 4 big stars. Then she draws 2 small stars. How many stars does Kate draw in all?
______ + _____ = ______
Answer:
6 stars
Explanation:
__4___ + __2___ = ___6___
Number of big stars =4
Number of small stars =2
Total number of stars =6

Make 10
Question 6.
Write an equation that shows this way to make a 10.
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 4
Answer:
8+2=10
___8___ + ___2__ = __10____
Explanation:

By adding 2 to 8 we get 10.

Pick a Project

PROJECT 1A
What has 8 legs and is big and hairy?
Project: Make an Insect and Spider Poster
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 5

Answer:
Spider
YARN SPIDER CRAFT – MATERIAL
Materials Required:
1. YARN
2. STRYO FOAM BALL
3.PIPE CLEANERS
4. CHOP STICKS
5.HOT GLUE
6.GOOGLY EYES
Step 1. Wrap yarn around your styro foam ball. Once you’re done, secure the yarn with a bit of hot glue.

Step 2. Take your skinny long object like a chopstick and pierce two holes, one on each side of your yarn ball.

Step 3. Insert your pipe cleaners (cut into “legs”) you should have 4 legs per side.

Step 4. Glue on your googly eyes.

 

Project 1B

Project: Collect Water Data
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 6

Water source Water volume, in cubic miles Water volume, in cubic kilometers Percent of
freshwater
Percent of
total water
Oceans, Seas, & Bays 321,000,000 1,338,000,000 96.54
Ice caps, Glaciers, & Permanent Snow 5,773,000 24,064,000 68.7 1.74
Groundwater 5,614,000 23,400,000 1.69
    Fresh 2,526,000 10,530,000 30.1   0.76
    Saline 3,088,000 12,870,000   0.93
Soil Moisture 3,959 16,500 0.05 0.001
Ground Ice & Permafrost 71,970 300,000 0.86 0.022
Lakes 42,320 176,400 0.013
    Fresh 21,830 91,000 0.26 0.007
    Saline 20,490 85,400 0.006
Atmosphere 3,095 12,900 0.04 0.001
Swamp Water 2,752 11,470 0.03 0.0008
Rivers 509 2,120 0.006 0.0002
Biological Water 269 1,120 0.003 0.0001

PROJECT 1C
Have you seen this different kind of art?
Project: Create a Shape Collage
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 7

Answer:
BRINGING THE CONCEPT OF DIFFERENT COLORS AND SHAPES
PROJECT;
BRINGING THE CONCEPT OF DIFFERENT COLORS AND SHAPES
Materials required:

  • Tissue paper (circles and squares)
  • Old art or paper scraps
  • Scissors
  • Cardstock
  • Clear glue or white glue
  • Bows, Brushes
    Process:
    Depending on the time you have or the interest of your child, you can either set out some pre-cut shapes, or you can let you child cut their own shapes. Each child’s artwork is unique and reflects their personality. I love how one child overlapped her tissue and created new colors. Another child was keen to keep everything very orderly. And another barely used any pre-cut shapes and instead, used the scissors like Matisse and cut his own shapes.
    art and math shape project
  • By making their own choices about color and composition, they are practicing their critical thinking skills.
    They are exploring basic shapes and abstract shapes while creatively putting together an image.
    This gives them an opportunity to associate shapes with real life objects.
  • When using the tissue paper, they are learning about transparency, and how colors can mix and overlap to make new colors.

3-ACT MATH PREVIEW

Math Modeling
Losing Marbles
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 8

Lesson 1.1 Addition Fact Strategies

Solve & Share
Use cubes. Show 2 + 5 and 5 + 2. Solve both problems. Explain how the problems are alike and how they are different.
I can … count on to add and add in any order.
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 9

Visual Learning Bridge
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 10

Convince Me! Does 5 + 2 = 2 + 5? How do you know?
Answer:
5+2=2+5=7
In additions there is no difference in addends, either from left to right the answer will be the same.

Guided Practice

Count on to find the sum. Then change the order of the addends.
Question 1.
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 11

Question 2.
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 12
Answer:
4+3=7
Explanation:
you can add numbers in any order and the sum is same, as shown below.

Independent Practice

Count on to find the sum. Then change the order of the addends. Use cubes if needed.
Question 3.
8 + 2 = ________
_______ + _______ = ________
Answer:
8+2=10
2+8=10
Explanation:

An equation uses an equal sign (=) to show that the value on the left is the same as the value on the right.

Question 4.
8 + 5 = ________
________ + ________ = ________
Answer:
8+5=13
5+8=13
Explanation:

An equation uses an equal sign (=) to show that the value on the left is the same as the value on the right.

Question 5.
9 + 3 = ________
________ + ________ = ________
Answer:
9+3=11
3+9=11
Explanation:

An equation uses an equal sign (=) to show that the value on the left is the same as the value on the right.

Question 6.
8 + 7 = ________
________ + ________ = ________
Answer:
8+7=15
7+8=15
Explanation:

An equation uses an equal sign (=) to show that the value on the left is the same as the value on the right.

Question 7.
7 + 10 = ________
________ + ________ = ________
Answer:
7+10=17
10+7=17
Explanation:

An equation uses an equal sign (=) to show that the value on the left is the same as the value on the right.

Question 8.
7 + 9 = ________
________ + ________ = ________
Answer:
7+9=16
9+7=16
Explanation:

An equation uses an equal sign (=) to show that the value on the left is the same as the value on the right.

Question 9.
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 13
Answer:
7+2=9
Explanation:
you can add numbers in any order and the sum is same, as shown below.

Question 10.
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 14
Answer:
6+2=8
Explanation:
you can add numbers in any order and the sum is same, as shown below.

Question 11.
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 15
Answer:
5+6=11
Explanation:
you can add numbers in any order and the sum is same, as shown below.

Question 12.
Algebra Write the missing numbers.
6 + ____ = 4 + 6
8 + 2 = ____ + 8

6 + ____ = 5 + 6
____ + 7 = 7 + 4

9 + 3 = 3 + ____
____ + 8 = 8 + 4
Answer:

Explanation:
you can add numbers in any order and the sum is same, in the above pattern.
Problem Solving

Solve the problems below.
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 16
Question 13.
Model Joy has 8 bean plants and 6 corn plants in her garden. How many plants does she have in all? Draw a picture to explain your thinking. Then write facts for this story with the addends in a different order.
____ + ____ = ____
____ + ____ = ____
Answer:
8+6=14
Explanation:

Question 14.
Higher Order Thinking Find the objects in Box I and Box 2 that are the same. Write an equation to show how many of each object there are. Then change the order of the addends.
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 17
Answer:

Question 15.
Assessment Practice which shows how to count on to find 7 + 5?
A. 7… 8, 9, 10, 11, 12
B. 1, 2, 3, 4, 5
C. 7 – 5
D. 7…8, 9, 10, 11
Answer:
Option A
Explanation:
Keep 7 in your mind and five fingers open, then count 8,9,10,11,12

Lesson 1.2 Doubles and Near Doubles

Solve & Share
Use counters. Show 6 + 6 = 12. Then show and explain how knowing that fact can help you find 6 + 7.
I can … use doubles and near doubles to add quickly and accurately.
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 18

Visual Learning Bridge
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 19

Convince Me! How could you use the doubles fact 7 + 7 to find 7 + 9?
Answer:
You can use a double fact in additions to add the addends.
Explanation:
7+8 is 1 more than 7+7
7+8=15
7+9 is 2 more than7+7
7+9=15
So these are near double facts.

Guided Practice

Complete the doubles facts. Use the doubles facts to solve the near doubles. Use cubes if needed.
Question 1.
2 + 2 = _______
2 + 3 = _______
Answer:
2+2=4
2+3=5
Explanation:
So these are near double facts.

Question 2.
_______ = 4 + 4
_______ = 4 + 5
Answer:
4+4=8
4+5=9
Explanation:
So these are near double facts.

Question 3.
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 20
Answer:

Explanation:
A near double is a math fact that is close to a doubles fact.
For example, 3+4 is considered a near double because it is close to the doubles fact 3+3.
Near doubles could be doubles plus one facts, doubles plus two facts, or doubles minus one facts.
So 6 and 7 are the nearest double facts.

Question 4.
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 21
Answer:

Explanation:
A near double is a math fact that is close to a doubles fact.
For example, 5+7 is considered a near double because it is close to the doubles fact 5+5.
Near doubles could be doubles plus one facts, doubles plus two facts, or doubles minus one facts.
So 10 and 12 are the nearest double facts.

Independent Practice

Complete the doubles facts. Use the doubles facts to solve the near doubles. Use cubes if needed.
Question 5.
6 + 6 = _______
6 + 7 = _______
Answer:
6+6=12
6+7=13
Explanation:

Question 6.
5 + 5 = _______
5 + 6 = _______
Answer:
5+5=10
5+6=11
Explanation:

Question 7.
8 + 8 = _______
8 + 10 = _______
Answer:
8 + 8 = 16
8 + 10 = 18
Explanation:

Question 8.
_______ = 1 + 1
_______ = 1 + 3
Answer:
2 = 1 + 1
4 = 1 + 3
Explanation:

Question 9.
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 22
Answer:

Explanation:
A near double is a math fact that is close to a doubles fact.
For example, 2+2 is considered a near double because it is close to the doubles fact 2+3.
Near doubles could be doubles plus one facts, doubles plus two facts, or doubles minus one facts.
So 4 and 5 are the nearest double facts.

Question 10.
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 23
Answer:

Explanation:
A near double is a math fact that is close to a doubles fact.
For example, 4+4 is considered a near double because it is close to the doubles fact 4+5.
Near doubles could be doubles plus one facts, doubles plus two facts, or doubles minus one facts.
So 8 and 9 are the nearest double facts.

Question 11.
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 24
Answer:

Explanation:
A near double is a math fact that is close to a doubles fact.
For example, 8+8 is considered a near double because it is close to the doubles fact 8+9.
Near doubles could be doubles plus one facts, doubles plus two facts, or doubles minus one facts.
So 16 and 17 are the nearest double facts.

Question 12.
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 25
Answer:

Explanation:
A near double is a math fact that is close to a doubles fact.
For example, 3+73is considered a near double because it is close to the doubles fact 3+5.
Near doubles could be doubles plus one facts, doubles plus two facts, or doubles minus one facts.
So 6 and 8 are the nearest double facts.

Question 13.
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 26
Answer:

Explanation:
A near double is a math fact that is close to a doubles fact.
For example, 5+5 is considered a near double because it is close to the doubles fact 5+7.
Near doubles could be doubles plus one facts, doubles plus two facts, or doubles minus one facts.
So 10 and 12 are the nearest double facts.

Question 14.
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 27
Answer:

Explanation:
A near double is a math fact that is close to a doubles fact.
For example, 7+7 is considered a near double because it is close to the doubles fact 7+9.
Near doubles could be doubles plus one facts, doubles plus two facts, or doubles minus one facts.
So 14 and 16 are the nearest double facts.

Question 15.
Algebra Complete. Then explain how you solved the problem.
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 28
Answer:

Explanation:
A near double is a math fact that is close to a doubles fact.
9+9is considered a near double because it is close to the doubles fact 9+10.
Near doubles could be doubles plus one facts, doubles plus two facts, or doubles minus one fact


Problem Solving
Solve the problems below.
Question 16.
Model John drew 4 houses. Then he drew 5 more houses. How many houses did John draw in all?
Draw a picture and write an equation to explain your thinking.
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 29 _______ houses
Answer:
9 houses
Explanation:

Question 17.
Higher Order Thinking Choose a doubles fact. Use that doubles fact to draw a picture that shows a near doubles story. Write the near doubles fact.
Answer:
Near doubles could be doubles plus one factsdoubles plus two facts, or doubles minus one facts.
Let’s take a look at the doubles fact 5+5. 5+6 would be the double plus one (5+5 plus one more).
5+7 would be the double plus two (5+5 plus two more).
23-Jul-2020

Question 18.
Assessment Practice Kate wants to find 6 + 7.
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 30
Which doubles fact will help her the most?
A. 4 + 4 = 8
B. 6 + 6 = 12
C. 8 + 8 = 16
D. 9 + 9 = 18
Answer:
Option B
6+6=12
6+7=13
6+7 is one more then 6+6

Lesson 1.3 Make a 10 to Add

Solve & Share
How can thinking about 10 help you find 9 + 3? Use the ten-frames and counters to show how.
I can … make a 10 to help me add quickly and accurately.
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 31

Visual Learning Bridge
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 32

Convince Me! Why do you move 2 counters to add 8 + 5?
Answer:
Addition can be thought of as combining two quantities and finding the total to add two plus eight combined five yellow counters and eight red counters. There are 13 counters in total.
Explanation:
8+5=13
10+3=13

Guided Practice

Make a 10 to add. Use counters and ten-frames.
Question 1.
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 33
Answer:
7+4=11
Explanation:

Independent Practice

Make a 10 to add. Use counters and ten-frames.
Question 2.
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 34
Answer:
8+4=12
Explanation:

Question 3.
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 35
Answer:
3+9=12
Explanation:

Question 4.
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 36
Answer:
6+7=13
Explanation:

Question 5.
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 37
Answer:
5+8=13

Question 6.
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 38
Answer:
7+5=12
Explanation:

Question 7.
5 + 9 = _______
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 39
Answer:
5+9=14
Explanation:

Question 8.
3 + 8 = ________
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 39
Answer:
3+8=11
Explanation:

Question 9.
4 + 9 = ______
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 39
Answer:
4+9=13
Explanation:

Question 10.
7 + 9 = _______
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 39
Answer:
7+9=16
Explanation:

Algebra Which number is missing?
Question 11.
8 + 5 = Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 40 + 3
Answer:
10 is missing
Explanation:
8+5=13
10+3=13

Question 12.
6 + 9 = 10 + Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 40
Answer:
5 is missing
Explanation:
6+9=15=10+5

Question 13.
8 + 9 = 10 + Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 40
Answer:
7 is missing
Explanation:
8+9=17=10+7

Question 14.
Higher Order Thinking Can you make a 10 to help you add 7 + 4 + 5? Explain.
Answer: 16

Explanation:
The maketen strategy is great for addition! It helps students understand place value and the relationships between numbers.
Ten-frames help students develop a good “mind picture” for the maketen strategy because our place-value system is based on making groups of ten.

Problem Solving

Solve the problems below. Show your work.
Question 15.
Tan’s team scored 16 points in a game. During the first half, they scored 9 points. How many points did the team score in the second half of the game?
_________ points
Answer:
Tan’s team score 7 points in second half.
Explanation:
Total points scored by Tan’s team = 16
In first half they scored = 9 points
In second half they scored (16-9)=7 points.

Question 16.
Make Sense The school has a clothing drive for charity. Ana’s class donates 8 coats. Nico’s class donates 5 hats. Adam’s class donates 8 coats. How many coats were donated in all?
_________ coats
Answer:
16 coats were donated in all.
Explanation:
No of coats donated by Ana’s class = 8
No of hats donated by Adam’s class = 5
No of coats donated by Nico’s class = 8
Total coats donated in all (8+8) = 16

Question 17.
Higher Order Thinking Draw a picture to show how you can make a 10 to help you add 3 + 5 + 9. Explain your picture to a friend.
Answer:

Question 18.
Assessment Practice Use the ten-frames. Show how to find 5 + 7 by making a 10. Then fill in the gray boxes.
Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 41
Answer: 12
Explanation:

Lesson 1.4 Addition Fact Patterns

Solve & Share
Look at the sums on an addition facts table for addends 0 to 5. Describe one of the patterns that you see. Use words, colors, or addition facts to describe the patterns.
I can … use the patterns on an addition facts table to help me remember the addition facts.
Envision Math Common Core 2nd Grade Answers Topic 1 Fluently Add and Subtract Within 20 42

Visual Learning Bridge
Envision Math Common Core 2nd Grade Answers Topic 1 Fluently Add and Subtract Within 20 43

Convince Me! How can patterns on an addition facts table help you remember the addition facts? Explain.
Answer:
The addition facts are all of the sums from 0+1 or 1+0 up to 10+10.
Explanation:
It’s essential that children master in sums, because they’re the foundation for the rest of elementary arithmetic.
Here’s the full addition facts chart is above shown picture.

Guided Practice

Use fact patterns to complete each equation.
Question 1.
Envision Math Common Core 2nd Grade Answers Topic 1 Fluently Add and Subtract Within 20 44

Question 2.
10+ ______ = 14
______ + 5 = 14
8 + 6 = ______
7 + ______ = 14
______ + 8 = 14
5 + ______ = 14
______ + 10 = 14
Answer:

Explanation:

By adding 4 to 10,9 to5,8 to 6, 7 to 7, 6 to 8, 5 to 9, 4 to 10 the answer will be 10 only.
So it tells the facts about number patterns.

Question 3.
9 + ______ = 9
______ + 1 = 9
7 + 2 = ______
6 + ______ = 9
______ + 4 = 9
5 + ______ = 9
______ + 3 = 9
______ + 2 = 9
8 + 1 = ______
______ + 0 = 9
Answer:

9+0=9
8+1=9
7+2=9
6+3=9
5+4=9
4+5=9
3+6=9
2+7=9
1+8=9
9+0=9
Explanation:

Independent Practice

Use fact patterns to complete each equation.
Question 4.
10 + ______ = 12
______ + 3 = 12
8 + 4 = ______
7 + ______ = 12
6 + 6 = ______
______ + 7 = 12
4+ ______ = 12
______ + 9 = 12
Answer:

10+2=12
9+3=12
8+4=12
7+5=12
6+6=12
5+7=12
4+8=12
3+9=12
Explanation:

Question 5.
7 + ______ = 7
______ + 1 = 7
5 + 2 = ______
______ + 3 = 7
______ + 4 = 7
______ + 5 = 7
______ + 6 = 7
0 + ______ = 7
Answer:
7+0=7
6+1=7
5+2=7
4+3=7
3+4=7
2+5=7
1+6=7
0+7=7
Explanation:

Question 6.
10+ ___ = 15
______ + 5 = 15
9 + 6 = ______
9 + ______ = 15
7 + ______ = 15
______ + 8 = 15
Answer:
10+ _5__ = 15
_10__ + 5 = 15
9 + 6 = _15__
9 + __6__ = 15
7 + __8__ = 15
_7_ + 8 = 15
Explanation:

Question 7.
Number Sense Find the 8 in the top row of the addition facts table. Complete all of the equations using the 8-column on the table. What pattern do you see?
8 + ______ = 8
8 + ______ = 9
8 + ______ = 10
8 + 3 = ______
8 + ______ = 12
8 +            =
8 + 6 = ______
8 + ______ = 15
8 + 8 = ______
8 + 10 = ______
Answer:

Explanation:

Problem Solving
Solve the problems below.
Question 8.
Reasoning Lucy is sorting items by their texture. She finds 6 items that are bumpy. Lucy finds 5 items that are smooth. How many items does Lucy find in all?
_________ items
Answer:
Lucy find 12 items in all.
Explanation:
Number of items that are bumpy = 6
Number of items that are smooth =5
Total items that Lucy had = 12

Question 9.
Vocabulary Look at the equation below. Circle the addends. Draw a square around the sum.
9 + 5 = 14
Answer:

Explanation:
In the above equation 9 and 5 are addends.
14 is the sum.
Question 10.
Higher Order Thinking Write 8 addition facts that have a sum of 12. How can the addition patterns help you? Explain.
Answer:
8+4=12
4+8=12

Explanation:

Question 11.
Assessment Practice which have a sum of 17? Choose all that apply.
Think about fact patterns.
☐ 10 + 7 = ?
☐ 7 + 6 = ?
☐ 9 + 8= ?
☐ 8 + 8 = ?
Answer:
10+7=17
9+8=17
Explanation:

Lesson 1.5 Count On and Count Back to Subtract

Solve & Share
How can counting help you find 12 – 4? Use the number line to show your work.
I can … count on and count back on a number line to subtract.
Envision Math Common Core 2nd Grade Answers Topic 1 Fluently Add and Subtract Within 20 45

Answer:
12-4=8
Explanation:

Start with greater number and count back 8 moves to find the difference.

Visual Learning Bridge
Envision Math Common Core 2nd Grade Answers Topic 1 Fluently Add and Subtract Within 20 46

Convince Me! How can you count back on a number line to find 9 – 5?
Answer:
9-5=4
Start with greater number and count back 5 moves to find the difference.
Explanation:

Subtraction of numbers using number line will help us to learn how a number line can be used for subtracting one number from the another number. Subtraction of numbers can be well understood with the help of the number line.

Guided Practice

Count on or count back to subtract. i.e Show your work on the number line.
Question 1.
Envision Math Common Core 2nd Grade Answers Topic 1 Fluently Add and Subtract Within 20 47

Question 2.
14 – 7 = Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 40
Envision Math Common Core 2nd Grade Answers Topic 1 Fluently Add and Subtract Within 20 48
Answer:
14-7=7
Explanation:

Independent Practice

Count on or count back to subtract. Show your work on the number line.
Question 3.
14 – 8 = Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 40
Envision Math Common Core 2nd Grade Answers Topic 1 Fluently Add and Subtract Within 20 48
Answer:
14-8=6
Explanation:

Question 4.
12 – 7 = Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 40
Envision Math Common Core 2nd Grade Answers Topic 1 Fluently Add and Subtract Within 20 48
Answer:
12-7=5
Explanation:

Question 5.
9 – 7 = Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 40
Envision Math Common Core 2nd Grade Answers Topic 1 Fluently Add and Subtract Within 20 48
Answer:
9-7=2
Explanation:

Question 6.
15 – 6 = Envision Math Common Core 2nd Grade Answer Key Topic 1 Fluently Add and Subtract Within 20 40
Envision Math Common Core 2nd Grade Answers Topic 1 Fluently Add and Subtract Within 20 48
Answer:
15-6=9
Explanation:

Question 7.
Higher Order Thinking How can you count on to find 13 – 4? Explain.
Answer:
13-4=9
Explanation:

Start with lesser number and count on to 13 to find the difference.

Problem Solving

Solve the problems below.
Question 8.
Callie had 18 seeds. She planted 10 of the seeds. How many seeds does Callie have now?
________ seeds
Answer:
After planting10 seeds Callie had 8 seeds.

Explanation:
Number of seeds = 18
Number seeds planted = 10
Total number of seeds left = 18-10=8

Question 9.
Make Sense Peter has 16 grapes. He eats some of the grapes. Peter has 10 grapes left. How many grapes did Peter eat?
________ grapes
Answer:
Peter ate 6 grapes.
Explanation:
Total number of grapes = 16
Number of grapes left = 10
Some of the grapes eaten by Peter = 16-10=6

Question 10.
Higher Order Thinking Choose 2 numbers. Use the numbers to write or draw a subtraction story. Write the equation you used to solve your story.
______ – _______ = ________
Answer:
9 – 7 = 2
Explanation:
Start with greater number and count back 2 moves to find the difference.

Question 11.
Assessment Practice Jake wants to find 6 – 3.
Use the numbers on the cards. Write them in the boxes to show how to use a number line to count on to solve.
Envision Math Common Core 2nd Grade Answers Topic 1 Fluently Add and Subtract Within 20 49
6 – 3 = _______
Answer:
6-3=3
Explanation:
Begin with greater number 6 and count on to lesser number 3, then difference is 3.

Lesson 1.6 Think Addition to Subtract

Solve & Share
How can you use an addition fact to find 14 – 6? Use counters to help show how.
I can … use addition to help me subtract quickly and accurately.
_____ + _______ = ________
So, 14 – 6 = _______

Answer:
6 + 8 = 14
14 – 6 =8
Explanation:
The basic facts of addition are those equations in which two single-digit numbers are combined by addition to give a sum. The missing number is the same in both equation.
Addition Fact  6+8=14
Subtraction Fact 14- 6 =8

Question 3.

Visual Learning Bridge
Envision Math Common Core 2nd Grade Answers Topic 1 Fluently Add and Subtract Within 20 50

Convince Me! How do you know which addition fact to use to complete the subtraction fact?
Answer:
In the case of addition and subtraction, you use three numbers and get four facts.

  1. For example, you can form a fact family using the three numbers 3, 10, and 13: 10 + 3 = 13, 3 + 10 = 13, 13 − 10 = 3, and 13 − 3 = 10.
  2. Addition facts − Here the sum of two of the three given numbers is the remaining third number.

Guided Practice

Think addition to help you subtract.
Question 1.
Envision Math Common Core 2nd Grade Answers Topic 1 Fluently Add and Subtract Within 20 51

Question 2.
9 – 3 = ?
3 + _______= 9
So, 9 – 3 = _______
Answer: 6
9 – 3 = 6
3 + 6= 9
So, 9 – 3 = 6
Explanation:
The basic facts of addition are those equations in which two single-digit numbers are combined by addition to give a sum. The missing number is the same in both equation.
Addition Fact 3+6=9
Subtraction Fact 9 – 3 = 6
So,9-3=6

Question 3.
14 – 5 =
5 + _____=4
So, 14 – 5 = _____
Answer: 9
14 – 5 = 9
5 +  9  = 14
So, 14 – 5 = 9
Explanation:
The basic facts of addition are those equations in which two single-digit numbers are combined by addition to give a sum. The missing number is the same in both equation.
Addition Fact 14-6=9
Subtraction Fact 5+9=14
So 14-5=9

Question 4.
12 – 4 = ?
4 + _______ = 12
So, 12 – 4 = _______
Answer: 8
12 – 4 = 8
4 + 8 = 12
So, 12 – 4 = 8
Explanation:
The basic facts of addition are those equations in which two single-digit numbers are combined by addition to give a sum. The missing number is the same in both equation.
Addition Fact 12-4=8
Subtraction Fact 4+8=12
So,12-4=8

Independent Practice

Subtract. Complete the addition fact that can help you.
Question 5.
8 – 1 = _______
1 + _______ = 8
Answer: 7
8 – 1 = 7
1 + 7 = 8
Explanation:
The basic facts of addition are those equations in which two single-digit numbers are combined by addition to give a sum.
Hence they range from 0+0=0 to 9+9=18.
For each basic addition fact there is a related basic subtraction fact.
Question 6.
10 – 2 = _______
2 + _______ = 10
Answer: 8
10 – 2 = 8
2 + 8= 10
Explanation:
Addition and subtraction are inverse operations because one operation can “undo” the other operation.
Adding 2 and 8 to get 10 is the opposite of 10 minus 2, leaving 8.

Question 7.
15 – 6 = _______
6 + _______ = 15
Answer: 9
15 – 6 = 9
6 + 9= 15
Explanation:
Addition and subtraction are inverse operations because one operation can “undo” the other operation.
Adding 6 and 9 to get 15 is the opposite of 15 minus 6, leaving 9.

Question 8.
17 – 7 = _______
7 + _______ = 17
Answer: 10
17 – 7 = 10
7 + 10 = 17
Explanation:
Addition and subtraction are inverse operations because one operation can “undo” the other operation.
Adding 7and 10 to get 17 is the opposite of 17 minus 7, leaving 17.

Question 9.
14 – 8 = _______
8 + _______ = 14
Answer: 6
14 – 8 = 6
8 + 6 = 14
Explanation:
Addition and subtraction are inverse operations because one operation can “undo” the other operation.
Adding 8 and 6 to get 14 is the opposite of 14 minus 8, leaving 6.

Question 10.
9 – 5 = _______
5 + _______ = 9
Answer: 4
9 – 5 = 4
5 + 4  = 9
Explanation:
Addition and subtraction are inverse operations because one operation can “undo” the other operation.
Adding 5 and 4 to get 9 is the opposite of 9 minus 5, leaving 4.

Question 11.
Envision Math Common Core 2nd Grade Answers Topic 1 Fluently Add and Subtract Within 20 52
Answer: 10

Explanation:
Addition and subtraction are inverse operations because one operation can “undo” the other operation.
Adding 8 and 10 to get 18 is the opposite of 18 minus 8, leaving 10
Question 12.
Envision Math Common Core 2nd Grade Answers Topic 1 Fluently Add and Subtract Within 20 53
Answer: 7

Explanation:
Addition and subtraction are inverse operations because one operation can “undo” the other operation.
Adding 9 and 7 to get 16 is the opposite of 16 minus 9, leaving 7

Question 13.
Envision Math Common Core 2nd Grade Answers Topic 1 Fluently Add and Subtract Within 20 54
Answer: 10

Explanation:
Addition and subtraction are inverse operations because one operation can “undo” the other operation.
Adding 10 and 9 to get 19 is the opposite of 19 minus 9, leaving 10
Higher Order Thinking
Write a related addition fact to complete the subtraction fact.
Question 14.
11 – _______ = 5
______ + ______ = _______
Answer:
11 – 6 =5
5 + 6 = 11
Explanation:
Addition and subtraction are inverse operations because one operation can “undo” the other operation.
Adding 5 and 6 to get 11 is the opposite of 11 minus 6, leaving 5

Question 15.
7 – _______ = 2
_______ + _______ = _______
Answer:
7 – 5 =2
2 + 5 = 7
Explanation:
Addition and subtraction are inverse operations because one operation can “undo” the other operation.
Adding 2 and 5 to get 7 is the opposite of 7 minus 5, leaving 2

Question 16.
12 – _______ = 8
_______ + _______ = _______
Answer:
12 – 4 =8
8 + 4 = 12
Explanation:
Addition and subtraction are inverse operations because one operation can “undo” the other operation.
Adding 8 and 4 to get 12 is the opposite of 12 minus 4, leaving 8

Problem Solving

Solve the problems below. Write an equation.
Question 17.
Reasoning Kate had 6 pens. She got 5 more pens from John. How many pens does Kate have in all?
Envision Math Common Core 2nd Grade Answers Topic 1 Fluently Add and Subtract Within 20 55
______ pens
Answer:11 pens


Explanation:
Number of pens Kate had 6
John gave 5 more pens
Total pens Kate has 11

Question 18.
Reasoning John had 11 pens. He gave 5 pens to Kate. How many pens does John have now?
Envision Math Common Core 2nd Grade Answers Topic 1 Fluently Add and Subtract Within 20 55
_______ pens
Answer: 6 pens

Explanation:
John had 11 pens.
John gave 5 pens to Kate.
Total pens does John have now is 6

Question 19.
Higher Order Thinking Write a subtraction story using the numbers 18 and 10. Then write an addition fact that can help you solve the problem in your story.
Answer:
Peter has 18 chocolates.
He eats 10 chocolates.
Now Peter has 18 chocolates in total.
18 – 10 = 8
10 + 8 = 18

Question 20.
Assessment Practice Pam has 16 cherries. She eats 7 cherries. Which addition fact can help you find how many cherries Pam has left?
Envision Math Common Core 2nd Grade Answers Topic 1 Fluently Add and Subtract Within 20 56
A. 7 + 4 = 11
B. 7 + 9 = 16
C. 7 + 6 = 13
D. 9 + 9 = 18
Answer:
Option B
Explanation:
16-7=11
11+7=16

Lesson 1.7 Make a 10 to Subtract

Solve & Share
14 ladybugs are on a leaf. 6 ladybugs fly away. How can thinking about 10 help you find how many ladybugs are left? Explain.
I can … make a 10 to help me subtract quickly and accurately.
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 57
Envision Math Common Core 2nd Grade Answers Topic 1 Fluently Add and Subtract Within 20 55

Visual Learning Bridge
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 58

Convince Me! Do you prefer to add first to get to 10 or subtract first to get to 10? Explain.
Answer:
Yes, i prefer addition first.
Explanation:
Add first to get 10 as shown in the above,
Then add 3 more to make 13.

Guided Practice

Make a 10 to subtract. Use counters and your workmat.
Question 1.
First add to get to 10.
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 59

Answer:7

Question 2.
First subtract to get to 10.
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 60
Answer: 9
Explanation:

Independent Practice

Make a 10 to subtract. Use counters and your workmat.

Think of the ways you know to make 10.
Question 3.
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 61
Answer: 7
Explanation:

Question 4.
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 62
Answer: 6
Explanation:

Question 5.

Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 63
Answer: 5
Explanation:

Question 6.
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 64
Answer: 8
Explanation:

Question 7.
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 65
Answer: 9
Explanation:

Question 8.
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 66
Answer: 9
Explanation:

Question 9.
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 67
Answer: 8
Explanation:

Question 10.
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 68
Answer: 9
Explanation:

Question 11.
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 69
Answer: 6
Explanation:

Question 12.
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 70
Answer: 7
Explanation:

Question 13.
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 71
Answer: 4
Explanation:

Question 14.
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 72
Answer: 7
Explanation:

Question 15.
Higher Order Thinking Carol subtracts 6 from 15. First, she adds to get to 10. Then she adds again to find her answer. Her answer is 10. Is Carol correct? Explain.
Answer: 9
No, her answer is wrong
Explanation :
15-6=9
she added 1 + 9 to get 10
She added again 5 +10 = 15

Problem Solving

Solve each problem. Which tool would you use?
Question 16.
Use Tools Chen had 12 animal stickers. He gave 5 of the stickers away. How many animal stickers does Chen have now?
________ animal stickers
Answer: 7 stickers
Explanation:

Question 17.
Use Tools Angie bought 13 strawberries. She ate 8 of the strawberries. How many strawberries does Angie have now?
________ strawberries
Answer: 5
Explanation:

Question 18.
Higher Order Thinking Show how you can make a 10 to find 17 – 9. Then explain your work.
Answer: 8
Explanation:

Question 19.
Assessment Practice Use the ten-frames. Show how to make a 10 to find 15 – 9. Start by subtracting to get to 10. Then complete the equations.
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 73
15 – _____ = 10
10 – _____ = _____
So, 15 – 9 =_____;
Answer:

15 – 5 = 10
10 – 4 = 6
15 – 9 =6
Explanation:

Lesson 1.8 Practice Addition and Subtraction Facts

Solve & Share
Write four related facts that use both the numbers 7 and 9 as quickly as you can. Hold up your hand when you are done. Then, tell how you found each fact.
I can … add and subtract quickly and accurately using mental math strategies.
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 74

9 + 7 = 16                       16 – 7 = 9
7 + 9 = 16                       16 – 9 = 7

Visual Learning Bridge
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 75

Convince Me! How can thinking about 10 help you find 14 – 8?
Answer : 6
Explanation:

Guided Practice

Add or subtract. Use any strategy.
Question 1.
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 76

Answer : 5
Explanation:

Question 2.
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 77
Answer: 8
Explanation:

Question 3.
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 78
Answer: 12
Explanation:

Question 4.
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 79
Answer: 5
Explanation:

Question 5.
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 80
Answer: 6
Explanation:

Question 6.
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 81
Answer: 18
Explanation:

Question 7.
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 82
Answer: 8
Explanation:

Question 8.
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 83
Answer: 20
Explanation:

Question 9.
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 84
Answer: 7
Explanation:

Question 10.
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 85
Answer: 10
Explanation:

Question 11.
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 86
Answer: 8
Explanation:

Question 12.
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 87
Answer: 8
Explanation:

Independent Practice

Add or subtract. Use any strategy.
Question 13.
14 – 7 = ________
Answer:
14-7=7
Explanation:
By subtracting smaller number 7 from greater number 14 we get the difference 7.

Question 14.
3 + 0 = ________
Answer:
3+0=3
Explanation:
By adding 3 to 0 we get the sum 3.

Question 15.
8 + 7 = ________
Answer:
8+7=15
Explanation:
By adding 8 to 7 we get the sum 15.

Question 16.
13 – 6 = ________
Answer:
13-6=7
Explanation:
By subtracting smaller number 6 from greater number 13 we get the difference 7.

Question 17.
10 + 9 = ________
Answer:
10+9=19
Explanation:
By adding 10 to 9 we get the sum 19.

Question 18.
17 – 8 = ________
Answer:
17-8=9
Explanation:
By subtracting smaller number 8 from greater number 17 we get the difference 9.

Question 19.
18 – 9 = ________
Answer:
18-9=9
Explanation:
By subtracting smaller number 9 from greater number 18 we get the difference 9.

Question 20.
9 – 1 = ________
Answer:
9-1=8
Explanation:
By subtracting smaller number 1 from greater number 9 we get the difference 8.

Question 21.
7 + 4 = ________
Answer:
7+4=11
Explanation:
By adding 7 to 4 we get the sum 11.

Question 22.
6 + 6 = ________
Answer:
6+6=12
Explanation:
By adding 6 to 6 we get the sum 12.

Question 23.
16 – 9 = ________
Answer:
16-9=7
Explanation:
By subtracting smaller number 9 from greater number 16 we get the difference 7.

Question 24.
20 – 10 = ________
Answer:
20-10=10
Explanation:
By subtracting smaller number 10 from greater number 20 we get the difference 10.

Question 25.
16 – 7 = ________
Answer:
16-7=9
Explanation:
By subtracting smaller number 7 from greater number 16 we get the difference 9.

Question 26.
15 – 8 = ________
Answer:
15-8=7
Explanation:
By subtracting smaller number 8 from greater number 15 we get the difference 7.

Question 27.
7 + 3 = ________
Answer:
7+3=10
Explanation:
By adding 3 to 7 we get the sum 10.

Question 28.
2 + 7 = ________
Answer:
2+7=9
Explanation:
By adding 2 to 7 we get the sum 9.

Question 29.
9 + 6 = ________
Answer:
9+6=15
Explanation:
By adding 9 to 6 we get the sum 15.

Question 30.
10 – 2 = ________
Answer:
10-2=8
Explanation:
By subtracting smaller number 2 from greater number 10 we get the difference 8.

Higher Order Thinking Write the missing number.
Question 31.
6 + ☐ = 14 – 5
Answer: 3
6 + 3 = 14 – 5

Question 32.
12 – 4 = ☐ + 2
Answer: 6
12 – 4 = 6 + 2

Question 33.
14 – ☐ = 5 + 4
Answer: 5
14 – 5 = 5 + 4

Problem Solving

Solve the problems below.
Question 34.
en Vision® STEM Danielle had 17 pieces of paper. She changed 8 of the pieces by cutting them. How many pieces were not changed? Write an equation to solve.
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 88
__________ pieces of paper
Answer: 9

Explanation:
Danielle had 17 piece.
She used 8 pieces for cutting.
After cutting no. of pieces left with her 9.
Question 35.
Model Diego saw 5 frogs on a rock. He also saw 7 frogs in the grass. How many frogs did Diego see in all? Write an equation to solve.
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 88
_______ frogs
Answer: 12

Explanation:
Number of frogs Diego saw on rock = 5
Number of frogs Diego saw in the grass = 7
Total number of frogs he saw together = 12
Question 36.
Higher Order Thinking Glen counts on to solve 9 + ☐ = 14. Explain how he can do this. What is the missing addend?
Answer: 5

Explanation:
Addition and subtraction are inverse operations because one operation can “undo” the other operation
Question 37.
Assessment Practice Choose a strategy to find 11 – 8. Explain how you used the strategy to find the difference.
Which strategy will you use to solve this problem?
Answer: 3
Explanation:

By using number line strategy, counting from bigger number to smaller number with back moves

Lesson 1.9 Solve Addition and Subtraction Word Problems

Solve & Share
Diego has 6 apples. Leslie has 9 apples. How many more apples does Leslie have than Diego? Will you add or subtract to solve this problem? Explain.
Answer:3
Leslie has 3 more apples.
Explanation:
By subtracting smaller number 6 from greater number 9 we get the difference 3.
I can … use addition and subtraction to solve word problems.
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 89

Visual Learning Bridge
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 90

Convince Me! Why can you use addition OR subtraction to solve the problem above?
Answer:
Addition and subtraction are inverse operations because one operation can “undo” the other operation.

Guided Practice

Write an equation to solve each problem. Use any strategy.
Question 1.
Sam has 5 red tomatoes and 3 green tomatoes. How many tomatoes does he have in all?
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 91
Answer: 8

Explanation:
By adding 3 to 5 we get the sum 8.

Question 2.
There are 16 party hats in a box. There are 10 party hats in a bag. How many fewer hats are in the bag than in the box?
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 92
______ fewer hats
Answer: 6

Explanation:
By subtracting smaller number 10 from bigger number 16, we get the difference 6.
Independent Practice

Write an equation to solve each problem. Use any strategy.
Question 3.
Cho has 3 more toy horses than Hakeem. Cho has 9 toy horses. How many toy horses does Hakeem have?
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 92
________ toy horses
Answer: 6

Explanation:
By subtracting smaller number 9 from bigger number 15, we get the difference 6.
Question 4.
There are 12 peaches in a bowl. The children eat some of them. Now there are 8 peaches. How many peaches did the children eat?
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 92
________ peaches were eaten.
Answer: 4

Explanation:
By subtracting smaller number 8 from bigger number 12, we get the difference 4.
Question 5.
Juan reads 5 books. Susan reads some books. They read 11 books in all. How many books did Susan read?
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 92
__________ books
Answer: 6

Explanation:
By subtracting smaller number 5 from bigger number 11, we get the difference 6.
Question 6.
Jack has 13 brushes. Igor has 6 brushes. How many fewer brushes does Igor have than Jack?
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 92
_______ fewer brushes
Answer: 7

Explanation:
By subtracting smaller number 6 from bigger number 13, we get the difference 7.
Question 7.
Number Sense Jen had 3 animal stickers in her collection. Her friend gave her 5 more stickers. Jen bought 7 more stickers. How many stickers does Jen have now? Show your work.
Answer:
15 stickers.
Explanation:
Jen had 3 animal stickers first and her friend gave 5 more, now she has total 8 stickers. Next
3 + 5 = 8
Jen bought 7 more and added to 8 animal stickers, now total 15 animal stickers.
8 +7 = 15

Problem Solving

Solve the problems below.
Question 8.
Higher Order Thinking Sandy has 8 markers. Alex has 6 fewer markers than Sandy. Jill has 2 markers. How many markers do they have in all? Show your work. Then explain how you found the answer.
Answer:
12 markers.
Explanation:
Sandy has 8 markers
Alex has 8 – 6 = 2 markers (subtract 6 from Sandy 8 markers as fewer or less)
Jill has 2 markers
Total 8 + 2 + 2 = 12

Use counters to solve.
Question 9.
Make Sense Annika saves 13 dimes. She put some of the dimes in a box and the rest in a jar. Write an equation to show one way she could have sorted the dimes.
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 92
________ dimes in a jar
________ dimes in a box
Answer:
Addition can be thought of as combining two quantities and finding the total to add 6 dimes plus 7 dimes combined counters. There are 13 counters in total.
Explanation:
6 + 7 = 13
7 + 6 =13
6 dimes in a jar
7 dimes in a box

Question 10.
Assessment Practice Maria had 5 rings. She bought some more rings. Now she has 12 rings. Choose Yes or No to show if the equation can be used to find how many more rings Maria bought.
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 93
Answer:
Maria brought 7 rings.
Explanation:

Lesson 1.10 Problem Solving

Construct Arguments
Solve & Share
How can you use the make a 10 strategy to find 7 + 9?
Explain your thinking and work. Use pictures, numbers, or words.
I can … use pictures, numbers, and words to explain why my thinking and work are correct.

Thinking Habits
How can I use math to explain why my work is correct?
Is my explanation clear?

Visual Learning Bridge
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 94

Convince Me! Are both math arguments above clear and complete? Explain.
Answer: YES
Explanation:
Double fact method is used
6+7 is one more then 6+6
6+6+1=13
6+7=13

Guided Practice

Use the picture to help you solve the problem. Then use words and numbers to make a math argument.
Question 1.
Is the sum of 9 + 5 the same as the sum of 10 + 4?
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 95
Answer:
9+5=14
10+4=14
Explanation:

Independent Practice

Solve each problem. Use words, pictures, and numbers to make a math argument.
Question 2.
Lynn had 14 grapes. She ate 8 of them. She wants to eat 6 more grapes. Will Lynn have enough grapes? Explain.
Answer: yes

Question 3.
The Lions scored 11 runs in a baseball game. The Tigers scored 7 runs. Did the Tigers score 3 fewer runs than the Lions? Explain.
Answer: yes
Explanation:
Number of runs scored by Lions = 11
Number of runs scored by Tigers = 7
By using equation 7 + 3 = 11
And 11 – 7 = 3

Question 4.
Complete the explanation below for how to find 8 + 9. Use pictures, words, or numbers to complete the explanation.
I know that 8 + 8 = 16.
Answer: 17

Problem Solving

Performance Task Puppies Sold The Sunset Pet Store sells puppies. The table shows how many puppies were sold Monday through Thursday.
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 96

Is the total number of puppies sold on Tuesday and Wednesday less than the number of puppies sold on Monday?
Answer : NO
Explanation:
Number of puppies sold Tuesday and Wednesday = 10 + 7 = 17
Number of puppies sold on Monday = 16
So the difference = 17 – 16 = 1
Question 5.
Make Sense Will you use all the numbers in the table to solve the problem? Explain.
Answer: NO

Explanation:
Puppies sold on Monday is 16
puppies sold on Tuesday and Wednesday 10+7=17

17 is 1 more then 16, So Puppies the total number of puppies sold on Tuesday and Wednesday not less than the number of puppies sold on Monday.

Question 6.
Model Write an equation to find the total number of puppies sold on Tuesday and Wednesday. Solve.
Answer:
10 + 7 = 17

Question 7.
Explain Solve the problem. Use words, pictures, and . numbers to explain your work and thinking.
Answer:
First count the puppies sold on Monday it is 16
then count the puppies sold on Tuesday and then add it to the puppies sold to Wednesday( 10 + 7 = 17)
comparing the puppies sold on Monday to the Tuesday and Wednesday
the answer is
the total number of puppies sold on Tuesday and Wednesday is one mote than the number of puppies sold on Monday.

Topic 1 Fluency Practice Activity

Find a Match
Find a partner. Point to a clue. Read the clue.
Look below the clues to find a match. Write the clue letter in the box next to the match.
Find a match for every clue.
I can … add and subtract within 20.

Clues
A. Near doubles with sums near 8
B. Every difference is 6.
C. Ways to make 12
D. Exactly two differences equal 9.
E. Every sum is greater than 14.
F. Exactly three differences are equal.
G. Near doubles with sums near 6
H. Every difference equals 14 – 7.
Envision Math Common Core Grade 2 Answer Key Topic 1 Fluently Add and Subtract Within 20 97

Read the clues carefully, you will get all answers
Answer:

Explanation:

A. Near doubles with sums near 8
Explanation:
3+4 = 7 or 4+3 = 7
3+4 is one more then 3+3 and the sum is near to 8
4+5 = 9 or 5+4 = 9
4+5 is one more then 4+4 and the sum is near to 8
So the clue is matched

B. Every difference is 6.
Explanation:
11-5 =6, 10-4 =6, 12-6 =6 and 9-3 =6
the difference is 6
So, the clue is Matched.

C. Ways to make 12
Explanation:
5+7=12, 6+6=12, 8+4=12 and 9+3=12
So, the clue is matched.

D. Exactly two differences equal 9.
Explanation:
9-0=9 and 16-7=9
So, the clue is matched.

E. Every sum is greater than 14.
Explanation:
8+9=17, 7+8=15, 8+7=15 and 6+9=15
So, the clue is matched

F. Exactly three differences are equal.
Explanation:
10-5=5, 12-7=5 and 13-8=5
So, the clue is matched.

G. Near doubles with sums near 6
Explanation:
4+3=7 or 3+4=7, 3+2=5 or 2+3=5
So, the clue is matched.

H. Every difference equals 14 – 7.
Explanation:
9-2=7, 13-6=7, 8-1=7 and 15-8=7
So, the clue is matched.

 

Topic 1 Vocabulary Review

Understand Vocabulary
Word List

  • addend
  • bar diagram
  • difference
  • doubles
  • equation
  • near doubles
  • sum

Question 1.
Circle a doubles fact.
7 + 7 = 14
6 + 7 = 13
7 + 0 = 7
Answer:

Question 2.
Circle a near doubles fact.
4 + 4 = 8
4 + 1 = 5
4 + 5 = 9
Answer:

Question 3.
Write a subtraction equation using numbers and symbols.
Answer:
9 – 4 = 5
7 – 4 = 3
Explanation:
By subtracting smaller number from bigger number we get the difference.

Question 4.
Find the sum of 8 + 6.
Answer: 14
8 + 6 = 14
Explanation:
By adding 6 to 8bwe get 14.

Question 5.
Find the difference of 12 – 5.
Answer: 7
12 – 5 = 7
Explanation:
By substracting smaller number 5 from bigger number 12 we get the difference 7.

Use Vocabulary in Writing

Question 6.
Describe how you can make a 10 to add 7 + 4. Use a term from the Word List.
Answer:
7 + 4 =11
Explanation:
7 and 4 are addends
11 is the sum
7 + 3 = 10
10 + 1 =11

Topic 1 Reteaching

Set A

You can count on to find a sum.
Envision Math Common Core Grade 2 Answers Topic 1 Fluently Add and Subtract Within 20 98

Count on to find the sum. Then change the order of the addends.
Question 1.
9 + 3 = ______
______ + ______ = ______
9 + 3 = ______ + ______
Answer:12
9 + 3 = 12
3 + 9 = 12
9 + 3 = 3 + 9
Explanation:
In additions if we change the addends from left to right or right to left the sum will be the same.

Question 2.
6 + 4 = ______
______ + ______ = ______
6 + 4 = ______ + ______
Answer: 10
6 + 4 = 10
4 + 6 = 10
6 + 4 = 4 + 6
Explanation:
In additions if we change the addends from left to right or right to left the sum will be the same.

Set B

You can use doubles to help you add a near double.
Envision Math Common Core Grade 2 Answers Topic 1 Fluently Add and Subtract Within 20 99

Complete the doubles facts. Use the doubles facts to solve the near doubles.
Question 3.
8 + 8 = ______
So, 7 + 8 = ______
Answer:
8 + 8 = 16
So, 7 + 8 =15
7 + 8 is one less then 8 + 8
Explanation:
According to double fact

Question 4.
5 + 5 = ______
So, 6 + 5 = ______
Answer:
5 + 5 = 10
6 + 5 = 11
6+5 is one more then 5+5
Explanation:

Set C

You can make a 10 to help you add 8 + 6.
Envision Math Common Core Grade 2 Answers Topic 1 Fluently Add and Subtract Within 20 100

Make a 10 to add.
Question 5.
8 + 4 = ?
Envision Math Common Core Grade 2 Answers Topic 1 Fluently Add and Subtract Within 20 101
Answer: 12
Explanation:

Set D

You can count on or count back to find 11 – 4.
Envision Math Common Core Grade 2 Answers Topic 1 Fluently Add and Subtract Within 20 102

Count on or count back to subtract. Show your work on the number line.
Question 6.
8 – 5 = ☐
Envision Math Common Core Grade 2 Answers Topic 1 Fluently Add and Subtract Within 20 103
Answer: 3

Explanation:
Start at 8 and count back 5 moves to get 3.
Question 7.
15 – 6 = ☐
Envision Math Common Core Grade 2 Answers Topic 1 Fluently Add and Subtract Within 20 103
Answer:9

Explanation:
Start at 15 and count back 6 moves to get 9.

Set E

You can think addition to help you subtract.
Find: 16 – 9 = ?
Think: 9 + 7
So, 16 – 9 = 7

Subtract. Write the addition fact that helped you.
Question 8.
13 – 7 = ______
7 + ______ = 13
Answer: 6
Explanation:
Double fact
13 – 7 = 6
7 + 6 = 13
6 + 7 = 13

Question 9.
17 – 9 = ______
9 + ______ = 17
Answer: 8
Explanation:
Double fact
17 – 9 = 8
9 + 8 = 17
8 + 9 = 17

Set F

You can make a 10 to subtract. Find 17 – 8.
Envision Math Common Core Grade 2 Answers Topic 1 Fluently Add and Subtract Within 20 104

Make a 10 to find 13 – 8. Draw counters to show your work.
Question 10.
Envision Math Common Core Grade 2 Answers Topic 1 Fluently Add and Subtract Within 20 105
13 – ______ = 10
10 – ______ = ______
13 – 8 = ______
Answer:
13 – 3 = 10
10 – 5 = 5
13 – 8 = 5
Explanation:

Set G

You can use addition or subtraction to solve word problems.
11 grapes are in a bowl. 9 grapes are in a cup. How many fewer grapes are in the cup?
11 – 9 = 2,
9 + 2 = 11
So, 2 fewer grapes are in the cup.

Write an equation to solve each problem.
Question 11.
13 shirts are in a closet. 8 shirts are in a box. How many more shirts are in the closet?
Envision Math Common Core Grade 2 Answers Topic 1 Fluently Add and Subtract Within 20 106
___5_____ more shirts
Answer:
5 shirts are there in the closet.
Explanation:

Question 12.
Drake has 10 more books than Yuri. Yuri has 10 books. How many books does Drake have?
Envision Math Common Core Grade 2 Answers Topic 1 Fluently Add and Subtract Within 20 106
________ books
Answer:
Drake have 20 books.
Explanation:

Set H

Thinking Habits
Construct Arguments
How can I use math to explain why my work is correct?
Did I use the correct numbers and symbols?
Envision Math Common Core Grade 2 Answers Topic 1 Fluently Add and Subtract Within 20 107

Solve. Use words, pictures, or numbers to construct arguments.

Question 13.
Tyler read 15 pages of a book. Ann read 9 pages of the same book. Did Tyler read 4 more pages than Ann? Explain.
Answer: No
Tyler read 6 more pages then Ann
Explanation:
15 – 9 = 6
Tyler read 15 pages
Ann read 9 pages
The difference is 6 pages

Topic 1 Assessment Practice

Question 1.
Tom draws 7 bugs. Gina draws 4 bugs. How many bugs did they draw in all?
Which shows how to count on to solve the problem?
A. 7…8, 9, 10, 11
B. 4…5, 6, 7
C. 7 + 4
D. 4 + 7
Answer: A
Explanation:
Keep 7 in mind 4 on fingers
after 7…count 8,9,10,11
Total 7+4=11 bugs

Question 2.
Lilly has 7 fish. Jack has 1 more fish than Lilly.
Which equations show how many fish in all? Choose all that apply.
☐ 7 + 7 + 7 = 21
☐ 7 + 1 = 8
☐ 7 + 7 + 1 = 15
☐ 7 + 7 = 14
☐ 7 + 8 = 15

Answer: 15
Explanation:
Double fact method
7+8 is one more then 7+7
7 + 8 = 15

Question 3.
Use the ten-frames. Show how to find the sum of 8 + 7 by making a 10. Then fill in the gray boxes.
Envision Math Common Core Grade 2 Answers Topic 1 Fluently Add and Subtract Within 20 108
Answer: 15
Explanation:

Question 4.
Which have a sum of 18? Choose all that apply.
☐ 10 + 8
☐ 8 + 10
☐ 9 + 8
☐ 8 + 8
☐ 9 + 9
Answer:
10 + 8 = 18
8 + 10 = 18
9 + 9 = 18

Question 5.
7 friends go to the movies. They have 4 tickets. How many more tickets do they need?
Draw lines to match each solution to how it was solved.
Envision Math Common Core Grade 2 Answers Topic 1 Fluently Add and Subtract Within 20 109
Answer:

Question 6.
Nita has 14 grapes. She eats 6 grapes.
Which addition fact can help you find how many grapes Nita has left?
A. 6 + 6 = 12
B. 6 + 7 = 13
C. 6 + 8 = 14
D. 8 + 8 = 16
Answer:
Option C
Explanation:
6 + 8 = 14
By adding 8 to 6 we get the sum 14.

Question 7.
Use the ten-frames. Show how to make a 10 to find 13 – 7. Then complete the equation.
Envision Math Common Core Grade 2 Answers Topic 1 Fluently Add and Subtract Within 20 110
13 – 7 = ______
Answer: 6

Question 8.
Bruce has some coins. He gives 4 coins to his brother. Now Bruce has 9 coins. How many coins did Bruce have at first? Write an equation to solve.
Envision Math Common Core Grade 2 Answers Topic 1 Fluently Add and Subtract Within 20 111
_________ coins
Answer:
Bruce have at first 13 coins.
Equation,

Question 9.
Maria has 4 pears. She buys some more pears. Now she has 12 pears. How many pears does Maria buy?
Part A
Draw a picture to model the problem.
Answer:
Maria brought 8 pears

Part B
Write an equation to solve the problem.
Envision Math Common Core Grade 2 Answers Topic 1 Fluently Add and Subtract Within 20 111
_________ pears
Answer:
8 pears

Question 10.
The team has 9 players. Then 2 players quit. After that, 5 players join the team. How many players does the team have now?
Use the numbers on the cards. Complete both equations to solve the problem.
Envision Math Common Core Grade 2 Answers Topic 1 Fluently Add and Subtract Within 20 112
Answer:
12 players

Question 11.
Choose Yes or No to show if 7 will make each equation true.
Envision Math Common Core Grade 2 Answers Topic 1 Fluently Add and Subtract Within 20 113
Answer:

Question 12.
Matt finds 9 sticks at the park. Mabel finds 7 sticks. How many sticks do they find in all? Write an equation to explain.
Envision Math Common Core Grade 2 Answers Topic 1 Fluently Add and Subtract Within 20 111
_________ sticks in all
Answer:
16 sticks

Question 13.
Choose Yes or No to show if 8 will make each equation true.
Envision Math Common Core Grade 2 Answers Topic 1 Fluently Add and Subtract Within 20 114
Answer: 8

Question 14.
Josh ate 6 fewer cherries than Gail. Gail ate 15 cherries. How many cherries did Josh eat?
Answer:
Josh ate 9 cherries
Explanation:
Number of cherries Gail ate = 15
Josh ate 6 fewer cherries than Gail.
Total number of cherries Josh ate = 15 – 6 = 9

Part A
Draw a picture to model the problem.
Answer:

Part B
Write an equation to solve the problem.
Envision Math Common Core Grade 2 Answers Topic 1 Fluently Add and Subtract Within 20 111
________ cherries
Answer:
9 cherries
Equation:

cherries

Question 15.
The table shows how many pictures 3 friends made.
Envision Math Common Core Grade 2 Answers Topic 1 Fluently Add and Subtract Within 20 115
Choose one of the friends. Write the name of the friend you choose.
How many pictures did that friend make?
Write an equation to solve the problem.
Envision Math Common Core Grade 2 Answers Topic 1 Fluently Add and Subtract Within 20 111
_________ pictures
Answer:
Brian, 13 pictures
Equation:

Topic 1 Performance Task

Farm Kittens
Many kittens are born each summer at the Sunshine Farm. The table shows the number of kittens born at the farm from June to August.
Envision Math Common Core Grade 2 Answers Topic 1 Fluently Add and Subtract Within 20 116
Question 1.
During which two months were a total of 20 kittens born?
Answer:
June + August
Explanation:

During the month of June and July
Answer: 21
Explanation:

Question 2.
Write an equation to find the total number of kittens born in July and August. Solve.
Answer: 15
Equation:

Question 3.
Joy said 5 more kittens were born in June than in August. Do you agree? Circle Yes or No. Show your work to explain.
Yes
No
Answer:
6 more kittens were born

Question 4.
Use the clues to complete the table below.

  • No kittens were born in December, January, and February.
  • In March, 6 kittens were born.
  • Three kittens were born in April and in September.
  • In May, 4 kittens were born.
  • Two kittens were born in October and in November
    Envision Math Common Core Grade 2 Answers Topic 1 Fluently Add and Subtract Within 20 117
    Answer:

Question 5.
Joy says that more kittens were born in the summer than in all other seasons combined. Is she correct? Explain.
Answer:
Yes, its correct
Explanation:
First add 13 + 4 = 17 (Kittens were born in the spring and Fall seasons)
Now subtract the above sum from the kittens born in summer
28 – 17 = 11

Question 6.
How many more kittens were born in the spring than in the fall? Show how to solve the problem with a subtraction equation.
Answer:
9 kittens
Equation:
13 – 4 = 9