Engage NY Eureka Math 1st Grade Module 1 Lesson 21 Answer Key
Eureka Math Grade 1 Module 1 Lesson 21 Problem Set Answer Key
Add the numbers on the pairs of cards. Write the number sentences. Color doubles red. Color doubles plus 1 blue.
Question 1.
Answer: 6
The above equation shows a pair of cards
ADD the pair of cards
By adding 3 and 3
we get 6
Question 2.
Answer:8
The above equation shows a pair of cards
ADD the pair of cards
By adding 4 wth 4
we get 8
Question 3.
Answer:7
The above equation shows a pair of cards
ADD the pair of cards
By adding 3 wth 4
we get 7
Question 4.
Answer:9
The above equation shows a pair of cards
ADD the pair of cards
By adding 5 wth 4
we get 9
Solve. Use your doubles to help. Draw and write the double that helped.
Question 5.
Answer: 9
Given the numbers are 5 and 4
To find the missing number
Add 5 with 4
we get 9
Question 6.
Answer:7
Given the numbers are 3 and 4
To find the missing number
Add 3 with 4
we get 7
Question 7.
Solve the doubles and the doubles plus 1 number sentences.
Answer:
Question 8.
Show how this strategy can help you solve 5 + 6 =
Answer:11
Given the numbers are 5 and 6
To find the missing number
Add 5 with 6
we get 11
Question 9.
Write a set of 4 related addition facts for the number sentences of Problem 7(d).
Answer: 4+4 =8
8+4+4
4+5=9
9=4+5
Eureka Math Grade 1 Module 1 Lesson 21 Exit Ticket Answer Key
Write the double and double plus 1 number sentence for each 5-group card.
Answer:
Eureka Math Grade 1 Module 1 Lesson 21 Homework Answer Key
Question 1.
Draw the 5-group card to show a double. Write the number sentence to match the cards.
a. 
Answer:The double fact that hlped to solve the euqation is
4+4=8
For which the double+1 fact is 4+5=9
b. 
Answer:The double fact that hlped to solve the euqation is
3+3=6
For which the double+1 fact is 3+4=7
c. 
Answer:The double fact that hlped to solve the euqation is
5+5=10
For which the double+1 fact is 5+6=11
Question 2.
Fill in the 5-group cards in order from least to greatest, double the number, and write the number sentences.
a. 
b. 
c. 
d. 
e. 
Answer:
Question 3.
Solve the number sentences.
a. 3 + 3 = __
Answer:6
Given : two numbers are 3 and 3
By adding 3 with 3 we get 6
3 + 3 = 6
b. 5 + __ = 10
Answer:10
Given : two numbers are 5 and 10
by subracting 5 from 10 we get 5
10-5=5
so the issing number is 5
5 + 5 = 10
c. 1 + __ = 2
Answer: 1
Given : two numbers are 1 and 2
by subracting 1 from 2 we get 1
2-1=1
so the issing number is 1
1+1=2
d. 4 = __ + 2
Answer:2
Given : two numbers are 4 and 2
by subracting 2 from 4 we get 2
4-2=2
so the issing number is 2
4 = 2 + 2
e. 8 = 4 + __
Answer:4
Given : two numbers are 4 and 8
by subracting 4 from 8 we get4
8-4=4
so the issing number is 5
8 = 4 + 4
Question 4.
Match the top cards to the bottom cards to show doubles plus 1.
a. 
b. 
c. 
d. 
Answer:
Question 5.
Solve the number sentences. Write the double fact that helped you solve the double plus 1.
a. 
Answer: The double +1 fact that hlped to solve the euqation is
2+3=5
For which the double fact is 2+2=4
b. 
Answer:The double +1 fact that hlped to solve the euqation is
3+4=7
For which the double fact is 3+3=6
c. 
Answer:The double +1 fact that hlped to solve the euqation is
4+5=9
For which the double fact is 4+4=8
