{"id":26684,"date":"2022-04-01T18:21:24","date_gmt":"2022-04-01T12:51:24","guid":{"rendered":"https:\/\/ccssmathanswers.com\/?p=26684"},"modified":"2022-04-07T11:20:31","modified_gmt":"2022-04-07T05:50:31","slug":"big-ideas-math-answers-grade-1-chapter-8","status":"publish","type":"post","link":"https:\/\/bigideasmathanswers.com\/big-ideas-math-answers-grade-1-chapter-8\/","title":{"rendered":"Big Ideas Math Answers Grade 1 Chapter 8 Add and Subtract Tens"},"content":{"rendered":"<p>Big Ideas Math Book 1st Grade Answer Key Chapter 8 Add and Subtract Tens helps the students to overcome the difficulties in math. Learning in a fun way will make maths more interesting to students. You can see step-by-step explanations for all the questions by using the figures. You can easily understand the concepts deeply with the help of our <a href=\"https:\/\/bigideasmathanswers.com\/big-ideas-math-answers-grade-1\/\">Big Ideas Math Answers Grade 1<\/a> Chapter 8 Add and Subtract Tens.<\/p>\n<h2>Big Ideas Math Book 1st Grade Answer Key Chapter 8 Add and Subtract Tens<\/h2>\n<p>In order to excel in the exam, we suggest the students of 1st standard refer to the Big Ideas Math Book 1st Grade Answer Key Chapter 8 Add and Subtract Tens. The topics shown in Big Ideas Math Answers Grade 1 Chapter 8 Add and Subtract Tens are as per the latest syllabus. Hit the links and start solving the problems using easy methods.<\/p>\n<p><strong>Vocabulary<\/strong><\/p>\n<ul>\n<li><a href=\"#Add_and_Subtract_Tens_Vocabulary\">Add and Subtract Tens Vocabulary<\/a><\/li>\n<\/ul>\n<p><strong>Lesson: 1 Mental Math: 10 More<\/strong><\/p>\n<ul>\n<li><a href=\"#Lesson_8.1_Mental_Math:_10_More\">Lesson 8.1 Mental Math: 10 More<\/a><\/li>\n<li><a href=\"#Mental_Math:_10_More_Practice_8.1\">Mental Math: 10 More Practice 8.1<\/a><\/li>\n<\/ul>\n<p><strong>Lesson: 2 Mental Math: 10 Less<\/strong><\/p>\n<ul>\n<li><a href=\"#Lesson_8.2_Mental_Math:_10_Less\">Lesson 8.2 Mental Math: 10 Less<\/a><\/li>\n<li><a href=\"#Mental_Math:_10_Less_Practice_8.2\">Mental Math: 10 Less Practice 8.2<\/a><\/li>\n<\/ul>\n<p><strong>Lesson: 3 Add Tens<\/strong><\/p>\n<ul>\n<li><a href=\"#Lesson_8.3_Add_Tens\">Lesson 8.3 Add Tens<\/a><\/li>\n<li><a href=\"#Add_Tens_Practice_8.3\">Add Tens Practice 8.3<\/a><\/li>\n<\/ul>\n<p><strong>Lesson: 4 Add Tens Using a Number Line<\/strong><\/p>\n<ul>\n<li><a href=\"#Lesson_8.4_Add_Tens_Using_a_Number_Line\">Lesson 8.4 Add Tens Using a Number Line<\/a><\/li>\n<li><a href=\"#Add_Tens_Using_a_Number_Line_Practice_8.4\">Add Tens Using a Number Line Practice 8.4<\/a><\/li>\n<\/ul>\n<p><strong>Lesson: 5 Subtract Tens<\/strong><\/p>\n<ul>\n<li><a href=\"#Lesson_8.5_Subtract_Tens\">Lesson 8.5 Subtract Tens<\/a><\/li>\n<li><a href=\"#Subtract_Tens_Practice_8.5\">Subtract Tens Practice 8.5<\/a><\/li>\n<\/ul>\n<p><strong>Lesson: 6 Subtract Tens Using a Number Line<\/strong><\/p>\n<ul>\n<li><a href=\"#Lesson_8.6_Subtract_Tens_Using_a_Number_Line\">Lesson 8.6 Subtract Tens Using a Number Line<\/a><\/li>\n<li><a href=\"#Subtract_Tens_Using_a_Number_Line_Practice_8.6\">Subtract Tens Using a Number Line Practice 8.6<\/a><\/li>\n<\/ul>\n<p><strong>Lesson: 7 Use Addition to Subtract Tens<\/strong><\/p>\n<ul>\n<li><a href=\"#Lesson_8.7_Use_Addition_to_Subtract_Tens\">Lesson 8.7 Use Addition to Subtract Tens<\/a><\/li>\n<li><a href=\"#Use_Addition_to_Subtract_Tens_Practice_8.7\">Use Addition to Subtract Tens Practice 8.7<\/a><\/li>\n<\/ul>\n<p><strong>Lesson: 8 Add Tens to a Number<\/strong><\/p>\n<ul>\n<li><a href=\"#Lesson_8.8_Add_Tens_to_a_Number\">Lesson 8.8 Add Tens to a Number<\/a><\/li>\n<li><a href=\"#Add_Tens_to_a_Number_Practice_8.8\">Add Tens to a Number Practice 8.8<\/a><\/li>\n<\/ul>\n<p><strong>Chapter: 8 Add and Subtract Tens<\/strong><\/p>\n<ul>\n<li><a href=\"#Add_and_Subtract_Tens_Performance_Task\">Add and Subtract Tens Performance Task<\/a><\/li>\n<li><a href=\"#Add_and_Subtract_Tens_Chapter_Practice\">Add and Subtract Tens Chapter Practice<\/a><\/li>\n<\/ul>\n<h3><a id=\"Add_and_Subtract_Tens_Vocabulary\"><\/a>Add and Subtract Tens Vocabulary<\/h3>\n<p><strong>Organize It<\/strong><\/p>\n<p>Review Words:<br \/>\ndecade numbers<br \/>\ndigits<\/p>\n<p>Use the review words to complete the graphic organizer.<\/p>\n<p><img loading=\"lazy\" class=\"alignnone size-full wp-image-26721\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-8-Add-and-Subtract-Tens-1.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 8 Add and Subtract Tens 1\" width=\"256\" height=\"262\" \/><br \/>\nThe ____________ of 16 are 1 and 6.<\/p>\n<p>Answer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33423\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Book-1st-Grade-Answer-key-Chapter-8-Add-and-Subtract-Tens-Add-and-Subtract-Tens-Vocabulary-1.png\" alt=\"Big-Ideas-Math-Book-1st-Grade-Answer-key-Chapter-8-Add-and-Subtract-Tens-Add-and-Subtract-Tens-Vocabulary\" width=\"318\" height=\"313\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Book-1st-Grade-Answer-key-Chapter-8-Add-and-Subtract-Tens-Add-and-Subtract-Tens-Vocabulary-1.png 318w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Book-1st-Grade-Answer-key-Chapter-8-Add-and-Subtract-Tens-Add-and-Subtract-Tens-Vocabulary-1-300x295.png 300w\" sizes=\"(max-width: 318px) 100vw, 318px\" \/><\/p>\n<p>The digits of 16 Are 1 and 6.<\/p>\n<p>Explanation:<br \/>\n10, 20, 30, 40 and so on are decade numbers.<br \/>\nAny of the numerals from 0 to 9, especially when forming part of a number are called as digits.<\/p>\n<p><strong>Define It<\/strong><\/p>\n<p>What am I?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26720\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-8-Add-and-Subtract-Tens-2.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 8 Add and Subtract Tens 2\" width=\"495\" height=\"153\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-8-Add-and-Subtract-Tens-2.png 495w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-8-Add-and-Subtract-Tens-2-300x93.png 300w\" sizes=\"(max-width: 495px) 100vw, 495px\" \/><\/p>\n<p>Answer:<\/p>\n<p><img loading=\"lazy\" class=\"alignnone size-full wp-image-33428\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Book-1st-Grade-Answer-key-Chapter-8-Add-and-Subtract-Tens-Define-It.png\" alt=\"Big-Ideas-Math-Book-1st-Grade-Answer-key-Chapter-8-Add-and-Subtract-Tens-Define It\" width=\"565\" height=\"240\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Book-1st-Grade-Answer-key-Chapter-8-Add-and-Subtract-Tens-Define-It.png 565w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Book-1st-Grade-Answer-key-Chapter-8-Add-and-Subtract-Tens-Define-It-300x127.png 300w\" sizes=\"(max-width: 565px) 100vw, 565px\" \/><\/p>\n<p>&nbsp;<\/p>\n<p>Explanation:<br \/>\n13 &#8211; 3 = 10= B\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 4 + 4 = 8 = P<br \/>\n5 + 1 = 6 = O\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a03 + 2 = 5 = L<br \/>\n5 + 4 = 9 = I\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 12 &#8211; 8 = 4 = R<br \/>\n6 &#8211; 4 = 2 = M\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a010 &#8211; 3 = U<br \/>\n1 + 2 = 3 = E<br \/>\n9 &#8211; 8 = 1 = N<br \/>\nHence , YOU are open number line.<\/p>\n<h3><a id=\"Lesson_8.1_Mental_Math:_10_More\"><\/a>Lesson 8.1 Mental Math: 10 More<\/h3>\n<p><strong>Explore and Grow<\/strong><\/p>\n<p>Find each sum. What do you notice?<\/p>\n<p>13 + 10 = __________<\/p>\n<p>39 + 10 = __________<\/p>\n<p>52 + 10 = __________<\/p>\n<p>Answer:<br \/>\n13 + 10 = 23<br \/>\n39 + 10 = 49<br \/>\n52 + 10 = 62<\/p>\n<p>Explanation:<br \/>\nAddition is bringing two or more numbers (or things) together to make a new total.<br \/>\nThe numbers to be added together are called the &#8220;Addends&#8221;:<br \/>\n1. Here, 13 and 10 are addends.<br \/>\nNow add both the numbers:<br \/>\n13 + 10 = 23.<br \/>\n2. Here, 39 and 10 are addends.<br \/>\n39 + 10 = 49.<br \/>\n3. Here, 52 and 10 are addends.<br \/>\n52 + 10 = 62.<br \/>\nHence, its noticed that total number of groups are 10 in all the counters.<\/p>\n<p><strong>Show and Grow<\/strong><\/p>\n<p>Use mental math.<\/p>\n<p>Question 1.<br \/>\n14 + 10 = __________<br \/>\nAnswer:<br \/>\n14 + 10 = 24<\/p>\n<p>Explanation:<br \/>\nHere, 14 and 10 are addends.<br \/>\nNow add both the numbers:<br \/>\n14 + 10 = 24.<br \/>\nHence, Sum = 24.<\/p>\n<p>Question 2.<br \/>\n46 + 10 = __________<br \/>\nAnswer:<br \/>\n46 + 10 =56.<\/p>\n<p>Explanation:<br \/>\nHere, 46 and 10 are addends.<br \/>\nNow add both the numbers:<br \/>\n46 + 10 = 56.<br \/>\nHence, Sum = 56.<\/p>\n<p>Question 3.<br \/>\n83 + 10 = __________<br \/>\nAnswer:<br \/>\n83 + 10 = 93.<\/p>\n<p>Explanation:<br \/>\nHere, 83 and 10 are addends.<br \/>\nNow add both the numbers:<br \/>\n83 + 10 = 93.<br \/>\nHence, Sum = 93.<\/p>\n<p>Question 4.<br \/>\n75 + 10 = __________<br \/>\nAnswer:<br \/>\n75 + 10 = 85.<\/p>\n<p>Explanation:<br \/>\nHere, 75 and 10 are addends.<br \/>\nNow add both the numbers:<br \/>\n75 + 10 = 85.<br \/>\nHence, sum = 85.<\/p>\n<p>Question 5.<br \/>\n21 + 10 = __________<br \/>\nAnswer:<br \/>\n21 + 10 = 31.<\/p>\n<p>Explanation:<br \/>\nHere, 21 and 10 are addends.<br \/>\nNow add both the numbers:<br \/>\n21 + 10 = 31.<br \/>\nHence, Sum = 31.<\/p>\n<p>Question 6.<br \/>\n60 + 10 = __________<br \/>\nAnswer:<br \/>\n60 + 10 = 70.<\/p>\n<p>Explanation:<br \/>\nHere, 60 and 10 are addends.<br \/>\nNow add both the numbers:<br \/>\n60 + 10 = 70.<br \/>\nHence, Sum = 70.<\/p>\n<p>Question 7.<br \/>\n10 + 89 = __________<br \/>\nAnswer:<br \/>\n10 + 89 = 99.<\/p>\n<p>Explanation:<br \/>\nHere, 10 and 89 are addends.<br \/>\nNow add both the numbers:<br \/>\n10 + 89 = 99.<br \/>\nHence, Sum = 99.<\/p>\n<p>Question 8.<br \/>\n10 + 68 = __________<br \/>\nAnswer:<br \/>\n10 + 68 = 78.<\/p>\n<p>Explanation:<br \/>\nHere, 10 and 68 are addends.<br \/>\nNow add both the numbers:<br \/>\n10 + 68 = 78.<br \/>\nHence, Sum = 78.<\/p>\n<p><strong>Apply and Grow: Practice<\/strong><\/p>\n<p>Use Mental math.<\/p>\n<p>Question 9.<br \/>\n16 + 10 = __________<br \/>\nAnswer:<br \/>\n16 + 10 = 26.<\/p>\n<p>Explanation:<br \/>\nHere, 16 and 10 are addends.<br \/>\nNow add both the numbers:<br \/>\n16 + 10 = 26.<br \/>\nHence, Sum = 26.<\/p>\n<p>Question 10.<br \/>\n63 + 10 = __________<br \/>\nAnswer:<br \/>\n63 + 10 = 73.<\/p>\n<p>Explanation:<br \/>\nHere, 63 and 10 are addends.<br \/>\nNow add both the numbers:<br \/>\n63 + 10 = 73.<br \/>\nHence, Sum = 73.<\/p>\n<p>Question 11.<br \/>\n8 + 10 = __________<br \/>\nAnswer:<br \/>\n8 + 10 = 18.<\/p>\n<p>Explanation:<br \/>\nHere, 8 and 10 are addends.<br \/>\nNow add both the numbers:<br \/>\n8 + 10 = 18.<br \/>\nHence, Sum = 18.<\/p>\n<p>Question 12.<br \/>\n44 + 10 = __________<br \/>\nAnswer:<br \/>\n44 + 10 = 54.<\/p>\n<p>Explanation:<br \/>\nHere, 44 and 10 are addends.<br \/>\nNow add both the numbers:<br \/>\n44 + 10 = 54.<br \/>\nHence, Sum = 54.<\/p>\n<p>Question 13.<br \/>\n19 + 10 = __________<br \/>\nAnswer:<br \/>\n19 + 10 = 29.<\/p>\n<p>Explanation:<br \/>\nHere, 19 and 10 are addends.<br \/>\nNow add both the numbers:<br \/>\n19 + 10 = 29.<br \/>\nHence, Sum = 29.<\/p>\n<p>Question 14.<br \/>\n59 + 10 = __________<br \/>\nAnswer:<br \/>\n59 + 10 = 69.<\/p>\n<p>Explanation:<br \/>\nHere, 59 and 10 are addends.<br \/>\nNow add both the numbers:<br \/>\n59 + 10 = 69.<br \/>\nHence, Sum = 69.<\/p>\n<p>Question 15.<br \/>\n10 + 22 = __________<br \/>\nAnswer:<br \/>\n10 + 22 = 32.<\/p>\n<p>Explanation:<br \/>\nHere, 10 and 22 are addends.<br \/>\nNow add both the numbers:<br \/>\n10 + 22 = 32.<br \/>\nHence, Sum = 32.<\/p>\n<p>Question 16.<br \/>\n10 + 50 = __________<br \/>\nAnswer:<br \/>\n10 + 50 = 60.<\/p>\n<p>Explanation:<br \/>\nHere, 10 and 50 are addends.<br \/>\nNow add both the numbers:<br \/>\n10 + 50 = 60.<br \/>\nHence, Sum = 60.<\/p>\n<p>Question 17.<br \/>\n10 + 71 = __________<br \/>\nAnswer:<br \/>\n10 + 71 = 81.<\/p>\n<p>Explanation:<br \/>\nHere, 10 and 71 are addends.<br \/>\nNow add both the numbers:<br \/>\n10 + 71 = 81.<br \/>\nHence, Sum = 81.<\/p>\n<p>Question 18.<br \/>\n10 + 38 = __________<br \/>\nAnswer:<br \/>\n10 + 38 = 48.<\/p>\n<p>Explanation:<br \/>\nHere, 10 and 38 are addends.<br \/>\nNow add both the numbers:<br \/>\n10 + 38 = 48.<br \/>\nHence, Sum = 48.<\/p>\n<p>Question 19.<br \/>\n55 + __________ = 65<br \/>\nAnswer:<br \/>\n55 + _10__ = 65<\/p>\n<p>Explanation:<br \/>\nHere, 55 and Missing number are addends.<br \/>\nSum is given = 65<br \/>\nLet the missing number be X.<br \/>\nNow add the numbers:<br \/>\n55 + X= 65<br \/>\nX = 65 &#8211; 55<br \/>\nX = 10.<br \/>\nHence, equation is \u00a055 + 10 = 65.<\/p>\n<p>Question 20.<br \/>\n87 + __________ = 97<br \/>\nAnswer:<br \/>\n87 + __10__ = 97<\/p>\n<p>Explanation:<br \/>\nHere, 87 and Missing number are addends.<br \/>\nSum is given = 97<br \/>\nLet the missing number be X.<br \/>\nNow add the numbers:<br \/>\n87 + X = 97<br \/>\nX = 97 &#8211; 87<br \/>\nX = 10.<br \/>\nHence, equation is 87 + 10 = 97.<\/p>\n<p>Question 21.<br \/>\n<strong>DIG DEEPER!<\/strong><br \/>\nUse each number once to complete the equations.<br \/>\n86\u00a0 \u00a0 \u00a0 \u00a076\u00a0 \u00a0 \u00a0 \u00a010\u00a0 \u00a0 \u00a0 \u00a0 \u00a066<br \/>\n_________ + 10 = __________\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 ___________ + __________ = 96<br \/>\nAnswer:<br \/>\n66 + 10 = 76<br \/>\n86 + 10 = 96<\/p>\n<p>Explanation:<br \/>\nThe numbers to be added together are called the &#8220;Addends&#8221;.<br \/>\n1.\u00a0 _________ + 10 = __________<br \/>\nWe know among two addends, one is 10.<br \/>\n2. \u00a0 \u00a0 ___________ + __________ = 96<br \/>\nGiven numbers 86,76,10,66.<br \/>\nPlace every given number next to given addend 10:<br \/>\n86 + 10 = 96<br \/>\n76 + 10 = 86<br \/>\n10 + 10 = 20<br \/>\n66 + 10 =76.<br \/>\nAmong this equations, for the first equation is\u00a0 66 + 10 =76.<br \/>\nand the second\u00a0 is 86 + 10 = 96 because the\u00a0 it fulfills the given condition. (Use each number once to complete the equations.)<\/p>\n<p><strong>Think and Grow: Modeling Real Life<\/strong><\/p>\n<p>There are 33 students on a bus. 10 more get on. How many students are on the bus now?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26853\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-8-Add-and-Subtract-Tens-3.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 8 Add and Subtract Tens 3\" width=\"211\" height=\"113\" \/><br \/>\nAddition equation:<\/p>\n<p>___________ students<\/p>\n<p>Answer:<br \/>\nTotal number of students on the bus now = 43.<br \/>\nGiven:<br \/>\nNumber of students in a bus = 33<br \/>\nNumber of students more got into the bus = 10<\/p>\n<p>Explanation:<br \/>\nTotal number of students on the bus now = Number of students in a bus + Number of students more get into the bus = 33 + 10<br \/>\n= 43.<br \/>\nHence, Total number of students on the bus now = 43.<\/p>\n<p><strong>Show and Grow<\/strong><\/p>\n<p>Question 22.<br \/>\nThere are 61 tents at a campground. 10 more are put up. How many tents are at the campground now?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26852\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-8-Add-and-Subtract-Tens-4.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 8 Add and Subtract Tens 4\" width=\"193\" height=\"152\" \/><br \/>\nAddition equation:<\/p>\n<p>____________ tents<\/p>\n<p>Answer:<br \/>\nNumber of tents at the campground now = 71.<\/p>\n<p>Given:<br \/>\nNumber of tents at a campground =61<br \/>\nNumber of tents more put up at the campground= 10<\/p>\n<p>Explanation:<br \/>\nNumber of tents at the campground now = Number of tents at a campground &#8211; Number of tents more put up at the campground<br \/>\n= 61 + 10<br \/>\n= 71<br \/>\nHence, Number of tents at the campground now = 71.<\/p>\n<h3><a id=\"Mental_Math:_10_More_Practice_8.1\"><\/a>Mental Math: 10 More Practice 8.1<\/h3>\n<p>Use Mental math.<\/p>\n<p>Question 1.<br \/>\n30 + 10 = __________<br \/>\nAnswer:<br \/>\n30 + 10 = 40<\/p>\n<p>Explanation:<br \/>\nHere, 30 and 10 are addends.<br \/>\nNow add both the numbers:<br \/>\n30 + 10 = 40<br \/>\nHence, Sum = 40.<\/p>\n<p>Question 2.<br \/>\n81 + 10 = __________<br \/>\nAnswer:<br \/>\n81 + 10 = 91<\/p>\n<p>Explanation:<br \/>\nHere, 81 and 10 are addends.<br \/>\nNow add both the numbers:<br \/>\n81 + 10 = 91.<br \/>\nHence, Sum = 91.<\/p>\n<p>Question 3.<br \/>\n6 + 10 = __________<br \/>\nAnswer:<br \/>\n6 + 10 = 16<\/p>\n<p>Explanation:<br \/>\nHere, 6 and 10 are addends.<br \/>\nNow add both the numbers:<br \/>\n6 + 10 = 16.<br \/>\nHence, Sum = 16.<\/p>\n<p>Question 4.<br \/>\n57 + 10 = __________<br \/>\nAnswer:<br \/>\n57 + 10 = 67<\/p>\n<p>Explanation:<br \/>\nHere, 57 and 10 are addends.<br \/>\nNow add both the numbers:<br \/>\n57 + 10 = 67.<br \/>\nHence, Sum = 67.<\/p>\n<p>Question 5.<br \/>\n48 + 10 = __________<br \/>\nAnswer:<br \/>\n48 + 10 = 58.<\/p>\n<p>Explanation:<br \/>\nHere, 48 and 10 are addends.<br \/>\nNow add both the numbers:<br \/>\n48 + 10 = 58.<br \/>\nHence, Sum = 58.<\/p>\n<p>Question 6.<br \/>\n26 + 10 = __________<br \/>\nAnswer:<br \/>\n26 + 10 = 36.<\/p>\n<p>Explanation:<br \/>\nHere, 26 and 10 are addends.<br \/>\nNow add both the numbers:<br \/>\n26 + 10 = 36.<br \/>\nHence, Sum = 36.<\/p>\n<p>Question 7.<br \/>\n10 + 43 = __________<br \/>\nAnswer:<br \/>\n10 + 43 = 53.<\/p>\n<p>Explanation:<br \/>\nHere, 10 and 43 are addends.<br \/>\nNow add both the numbers:<br \/>\n10 + 43 = 53.<br \/>\nHence, Sum = 53.<\/p>\n<p>Question 8.<br \/>\n10 + 65 = __________<br \/>\nAnswer:<br \/>\n10 + 65 = 75.<\/p>\n<p>Explanation:<br \/>\nHere, 10 and 65 are addends.<br \/>\nNow add both the numbers:<br \/>\n10 + 65 = 75.<br \/>\nHence, Sum = 75.<\/p>\n<p>Question 9.<br \/>\n10 + 82 = __________<br \/>\nAnswer:<br \/>\n10 + 82 = 92.<\/p>\n<p>Explanation:<br \/>\nHere, 10 and 82 are addends.<br \/>\nNow add both the numbers:<br \/>\n10 + 82 = 92.<br \/>\nHence, Sum = 92.<\/p>\n<p>Question 10.<br \/>\n10 + 79 = __________<br \/>\nAnswer:<br \/>\n10 + 79 = 89.<\/p>\n<p>Explanation:<br \/>\nHere, 10 and 79 are addends.<br \/>\nNow add both the numbers:<br \/>\n10 + 79 = 89.<br \/>\nHence, Sum = 89.<\/p>\n<p>Question 11.<br \/>\n22 + __________ = 32<br \/>\nAnswer:<br \/>\n22 + 10 =32.<\/p>\n<p>Explanation:<br \/>\nHere, 22 and Missing number are addends.<br \/>\nLet the missing number be X.<br \/>\nSum is given =32<br \/>\nNow add the numbers:<br \/>\n22 + X = 32<br \/>\nX = 32 &#8211; 22<br \/>\nX = 10.<br \/>\nHence, equation is 22 + 10 =32.<\/p>\n<p>Question 12.<br \/>\n85 + __________ = 95<br \/>\nAnswer:<br \/>\n85 + 10 = 95.<\/p>\n<p>Explanation:<br \/>\nHere, 85 and Missing number are addends.<br \/>\nLet the missing number be X.<br \/>\nSum is given = 95<br \/>\nAdd the numbers.<br \/>\n85 + X = 95<br \/>\nX = 95 &#8211; 85<br \/>\nX = 10.<br \/>\nHence, equation is 85 + 10 = 95.<\/p>\n<p>Question 13.<br \/>\n64 + __________ = 74<br \/>\nAnswer:<br \/>\n64 + 10 = 74.<\/p>\n<p>Explanation:<br \/>\nHere, 64 and Missing number are addends.<br \/>\nLet the missing number be X.<br \/>\nSum is given = 74.<br \/>\nAdd the numbers.<br \/>\n64 + X = 74<br \/>\nX = 74 &#8211; 64<br \/>\nX = 10.<br \/>\nHence, equation\u00a0 is 64 + 10 = 74.<\/p>\n<p>Question 14.<br \/>\n41 + __________ = 51<br \/>\nAnswer:<br \/>\n41 + 10 = 51.<\/p>\n<p>Here, 41 and Missing number are addends.<br \/>\nLet the missing number be X.<br \/>\nSum is given = 51.<br \/>\nAdd the numbers.<br \/>\n41 + X = 51<br \/>\nX = 51 &#8211; 41<br \/>\nX = 10.<br \/>\nHence, equation is 41 + 10 = 51 .<\/p>\n<p>Question 15.<br \/>\n<strong>DIG DEEPER!<\/strong><br \/>\nUse each number once to complete the equations.<br \/>\n25\u00a0 \u00a0 \u00a0 \u00a0 10\u00a0 \u00a0 \u00a0 \u00a015\u00a0 \u00a0 \u00a0 \u00a035<br \/>\n10 + __________ = _________\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 25 + __________ = ___________<br \/>\nAnswer:<br \/>\n10 + 15 = 25<br \/>\n25 +10 = 35<\/p>\n<p>Explanation:<br \/>\nThe numbers to be added together are called the &#8220;Addends&#8221;.<br \/>\n1. 10 + __________ = _________<br \/>\n2. 25 + __________ = ___________<br \/>\nGiven 10 and 25 as one of the addends among two addends in their respective addition.<br \/>\nGiven numbers 25,10,15,35 are other addends.<br \/>\nCheck out placing each addend next to 10.<br \/>\nEquation are ,<br \/>\n10 + 25 = 35<br \/>\n10 + 10 = 20<br \/>\n10 + 15 = 25<br \/>\n10 + 35 =45.<br \/>\nAmong this equations, for the first equation is 10 + 15 = 25<br \/>\nand the second\u00a0 is 25 + 10 = 35 because the\u00a0 it fulfills the given condition .(Use each number once to complete the equations.)<\/p>\n<p>Question 16.<br \/>\n<strong>Modeling Real Life<\/strong><br \/>\nThere are 142 teachers at a school. The school hires 10 more. How many teachers are there now?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26851\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-8-Add-and-Subtract-Tens-5.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 8 Add and Subtract Tens 5\" width=\"97\" height=\"96\" \/><\/p>\n<p>_____________ teachers<br \/>\nAnswer:<br \/>\nNumber of teachers are there now = 152.<\/p>\n<p>Given:<br \/>\nNumber of teachers at a school = 142<br \/>\nNumber of teachers the school hired more = 10<\/p>\n<p>Explanation:<br \/>\nNumber of teachers are there now = Number of teachers at a school + Number of teachers the school hired more<br \/>\n= 142 + 10<br \/>\n= 152.<br \/>\nHence, Number of teachers are there now = 152.<\/p>\n<p><strong>Review &amp; Refresh<\/strong><\/p>\n<p>Question 17.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26850\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-8-Add-and-Subtract-Tens-6.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 8 Add and Subtract Tens 6\" width=\"164\" height=\"87\" \/><br \/>\n10 less than 87 is _________ .<br \/>\nAnswer:<br \/>\n87 &#8211; 10 = 77.<\/p>\n<p>Explanation:<br \/>\nThere are 87 mangoes in a\u00a0 basket.<br \/>\n10 mangoes got spoiled. How many mangoes left??<br \/>\nSubtract the mangoes<br \/>\n87 &#8211; 10 = 77.<br \/>\nHence, equation is 87 &#8211; 10 = 77.<\/p>\n<p>Question 18.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26849\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-8-Add-and-Subtract-Tens-7.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 8 Add and Subtract Tens 7\" width=\"72\" height=\"88\" \/><br \/>\n1 less than 33 is __________ .<br \/>\nAnswer:<br \/>\n33 &#8211; 1 = 32<\/p>\n<p>Explanation:<br \/>\nThere are 33 mangoes in a\u00a0 basket.<br \/>\n1 mango got spoiled. How many mangoes left??<br \/>\nSubtract the mangoes<br \/>\n33 &#8211; 1 = 32.<br \/>\nHence, equation is 33 &#8211; 1 = 32.<\/p>\n<h3><a id=\"Lesson_8.2_Mental_Math:_10_Less\"><\/a>Lesson 8.2 Mental Math: 10 Less<\/h3>\n<p><strong>Explore and Grow<\/strong><\/p>\n<p>Find each difference. What do you notice?<\/p>\n<p>33 &#8211; 10 = __________<\/p>\n<p>67 &#8211; 10 = __________<\/p>\n<p>82 &#8211; 10 = __________<br \/>\nAnswer:<br \/>\n33\u00a0 -10 = 23<br \/>\n67 &#8211; 10 = 57<br \/>\n82 &#8211; 10 = 72<\/p>\n<p>Explanation:<br \/>\n1. The number that is to be subtracted from is called Minuend.<br \/>\nThe number that is to be subtracted is called Subtrahend:<br \/>\nThe result of subtracting one number from another is called Difference:<br \/>\nIn this case, 33 is minuend and 10 is subtrahend.<br \/>\nNow subtract this two:<br \/>\n=&gt; 33\u00a0 -10 = 23<br \/>\nHence, difference is \u00a023.<br \/>\n2. In this case, 67 is minuend and 10 is subtrahend.<br \/>\nNow subtract this two:<br \/>\n=&gt; 67 &#8211; 10 = 57<br \/>\nHence, difference is 57.<br \/>\n3. In this case, 82 is minuend and 10 is subtrahend.<br \/>\nNow subtract this two:<br \/>\n=&gt; 82 &#8211; 10 = 72<br \/>\nHence, difference is 72.<\/p>\n<p><strong>Show and Grow<\/strong><\/p>\n<p>Use mental math.<\/p>\n<p>Question 1.<br \/>\n55 &#8211; 10 = __________<br \/>\nAnswer:<br \/>\n55 &#8211; 10 = 45<\/p>\n<p>Explanation:<br \/>\nIn this case, 55 is minuend and 10 is subtrahend.<br \/>\nNow subtract this two:<br \/>\n55 &#8211; 10 = 45<br \/>\nHence, Difference = 45.<\/p>\n<p>Question 2.<br \/>\n21 &#8211; 10 = __________<br \/>\nAnswer:<br \/>\n21 &#8211; 10 = 11<\/p>\n<p>Explanation:<br \/>\nIn this case, 21 is minuend and 10 is subtrahend.<br \/>\nNow subtract this two:<br \/>\n21 &#8211; 10 = 11<br \/>\nHence, Difference = 11.<\/p>\n<p>Question 3.<br \/>\n18 &#8211; 10 = __________<br \/>\nAnswer:<br \/>\n18 &#8211; 10 =8.<\/p>\n<p>Explanation:<br \/>\nIn this case, 18 is minuend and 10 is subtrahend.<br \/>\nNow subtract this two:<br \/>\n18 &#8211; 10 =8.<br \/>\nHence, Difference = 8.<\/p>\n<p>Question 4.<br \/>\n74 &#8211; 10 = __________<br \/>\nAnswer:<br \/>\n74 &#8211; 10 = 64.<\/p>\n<p>Explanation:<br \/>\nIn this case, 74 is minuend and 10 is subtrahend.<br \/>\nNow subtract this two:<br \/>\n74 &#8211; 10 = 64.<br \/>\nHence, Difference = 64.<\/p>\n<p>Question 5.<br \/>\n89 &#8211; 10 = __________<br \/>\nAnswer:<br \/>\n89 &#8211; 10 = 79.<\/p>\n<p>Explanation:<br \/>\nIn this case, 89 is minuend and 10 is subtrahend.<br \/>\nNow subtract this two:<br \/>\n89 &#8211; 10 = 79.<br \/>\nHence, Difference = 79.<\/p>\n<p>Question 6.<br \/>\n72 &#8211; 10 = __________<br \/>\nAnswer:<br \/>\n72 &#8211; 10 = 62.<\/p>\n<p>Explanation:<br \/>\nIn this case, 72 is minuend and 10 is subtrahend.<br \/>\nNow subtract this two:<br \/>\n72 &#8211; 10 = 62.<br \/>\nHence, Difference = 62.<\/p>\n<p><strong>Apply and Grow: Practice<\/strong><\/p>\n<p>Use mental math<\/p>\n<p>Question 7.<br \/>\n60 &#8211; 10 = __________<br \/>\nAnswer:<br \/>\n60 &#8211; 10 = 50.<\/p>\n<p>Explanation:<br \/>\nIn this case, 60 is minuend and 10 is subtrahend.<br \/>\nNow subtract this two:<br \/>\n60 &#8211; 10 = 50.<br \/>\nHence, Difference = 50.<\/p>\n<p>Question 8.<br \/>\n45 &#8211; 10 = __________<br \/>\nAnswer:<br \/>\n45 &#8211; 10 = 35<\/p>\n<p>Explanation:<br \/>\nIn this case, 45 is minuend and 10 is subtrahend.<br \/>\nNow subtract this two:<br \/>\n45 &#8211; 10 = 35<br \/>\nHence, Difference = 35.<\/p>\n<p>Question 9.<br \/>\n50 &#8211; 10 = __________<br \/>\nAnswer:<br \/>\n50 &#8211; 10 = 40<\/p>\n<p>Explanation:<br \/>\nIn this case, 50 is minuend and 10 is subtrahend.<br \/>\nNow subtract this two:<br \/>\n50 &#8211; 10 = 40<br \/>\nHence, Difference = 40.<\/p>\n<p>Question 10.<br \/>\n34 &#8211; 10 = __________<br \/>\nAnswer:<br \/>\n34 &#8211; 10 = 24<\/p>\n<p>Explanation:<br \/>\nIn this case, 34 is minuend and 10 is subtrahend.<br \/>\nNow subtract this two:<br \/>\n34 &#8211; 10 = 24<br \/>\nHence, Difference = 24.<\/p>\n<p>Question 11.<br \/>\n51 &#8211; 10 = __________<br \/>\nAnswer:<br \/>\n51 &#8211; 10 = 41<\/p>\n<p>Explanation:<br \/>\nIn this case, 51 is minuend and 10 is subtrahend.<br \/>\nNow subtract this two:<br \/>\n51 &#8211; 10 = 41<br \/>\nHence, Difference = 41.<\/p>\n<p>Question 12.<br \/>\n86 &#8211; 10 = __________<br \/>\nAnswer:<br \/>\n86 &#8211; 10 = 76.<\/p>\n<p>Explanation:<br \/>\nIn this case, 86 is minuend and 10 is subtrahend.<br \/>\nNow subtract this two:<br \/>\n86 &#8211; 10 = 76.<br \/>\nHence, Difference = 76.<\/p>\n<p>Question 13.<br \/>\n64 &#8211; 10 = __________<br \/>\nAnswer:<br \/>\n64 &#8211; 10 = 54.<\/p>\n<p>Explanation:<br \/>\nIn this case, 64 is minuend and 10 is subtrahend.<br \/>\nNow subtract this two:<br \/>\n64 &#8211; 10 = 54.<br \/>\nHence, Difference = 54.<\/p>\n<p>Question 14.<br \/>\n97 &#8211; 10 = __________<br \/>\nAnswer:<br \/>\n97 &#8211; 10 = 87.<\/p>\n<p>Explanation:<br \/>\nIn this case, 97 is minuend and 10 is subtrahend.<br \/>\nNow subtract this two:<br \/>\n97 &#8211; 10 = 87.<br \/>\nHence, Difference = 87.<\/p>\n<p>Question 15.<br \/>\n28 &#8211; 10 = __________<br \/>\nAnswer:<br \/>\n28 &#8211; 10 = 18.<\/p>\n<p>Explanation:<br \/>\nIn this case, 28 is minuend and 10 is subtrahend.<br \/>\nNow subtract this two:<br \/>\n28 &#8211; 10 = 18.<br \/>\nHence, Difference = 18.<\/p>\n<p>Question 16.<br \/>\n73 &#8211; 10 = __________<br \/>\nAnswer:<br \/>\n73 &#8211; 10 = 63.<\/p>\n<p>Explanation:<br \/>\nIn this case, 73 is minuend and 10 is subtrahend.<br \/>\nNow subtract this two:<br \/>\n73 &#8211; 10 = 63.<br \/>\nHence, Difference = 63.<\/p>\n<p>Question 17.<br \/>\n__________ &#8211; 10 = 22<br \/>\nAnswer:<br \/>\n32 &#8211; 10 = 22.<\/p>\n<p>Explanation:<br \/>\nIn this case, Missing number is minuend and 10 is subtrahend.<br \/>\nLet missing number be X.<br \/>\nSum is given = 22<br \/>\nNow subtract:<br \/>\nX &#8211; 10 = 80<br \/>\nX = 22 + 10<br \/>\nX = 32.<br \/>\nHence, Equation = 32 &#8211; 10 = 22 .<\/p>\n<p>Question 18.<br \/>\n__________ &#8211; 10 = 80<br \/>\nAnswer:<br \/>\n90 &#8211; 10 = 80.<\/p>\n<p>Explanation:<br \/>\nIn this case, Missing number is minuend and 10 is subtrahend.<br \/>\nLet missing number be X.<br \/>\nSum is given = 80.<br \/>\nNow subtract :<br \/>\nX &#8211; 10 = 80<br \/>\nX = 80 + 10<br \/>\nX = 90.<br \/>\nHence, Equation = 90 &#8211; 10 = 80.<\/p>\n<p>Question 19.<br \/>\n<strong>YOU BE THE TEACHER<\/strong><br \/>\nIs Newton correct? Explain.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26869\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-8.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 8 Add and Subtract Tens 8\" width=\"475\" height=\"148\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-8.png 475w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-8-300x93.png 300w\" sizes=\"(max-width: 475px) 100vw, 475px\" \/><br \/>\nAnswer:<br \/>\n94 &#8211; 10 = 84.<\/p>\n<p>Explanation:<br \/>\nIn this case, 94 is minuend and 10 is subtrahend.<br \/>\nNow subtract this two:<br \/>\n94 &#8211; 10 = 84.<br \/>\nHence, Difference = 84.<br \/>\nTherefore, Newton is correct.<\/p>\n<p><strong>Think and Grow: Modeling Real Life<\/strong><\/p>\n<p>You want to ride all 47 rides at an amusement park. You ride 10 of them. How many rides are left?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26868\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-9.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 8 Add and Subtract Tens 9\" width=\"166\" height=\"133\" \/><br \/>\nSubtraction equation:<\/p>\n<p>_________ rides.<\/p>\n<p>Answer:<br \/>\nNumber of rides left = 37.<\/p>\n<p>Given:<br \/>\nTotal number of rides you want to ride at an amusement park = 47<br \/>\nNumber of rides you have taken out of them = 10<\/p>\n<p>Explanation:<br \/>\nNumber of rides left = Total number of rides you want to ride at an amusement park &#8211; Number of rides you have taken out of them<br \/>\n= 47 &#8211; 10<br \/>\n= 37.<br \/>\nHence, Number of rides left = 37.<\/p>\n<p><strong>Show and Grow<\/strong><\/p>\n<p>Question 20.<br \/>\nYou want to try all 65 flavors at a frozen yogurt shop. You try 10 of them. How many flavors are left?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26867\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-10.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 8 Add and Subtract Tens 10\" width=\"90\" height=\"96\" \/><br \/>\nSubtraction equation:<\/p>\n<p>_________ flavors.<\/p>\n<p>Answer:<br \/>\nNumber of flavors left = 55.<\/p>\n<p>Given:<br \/>\nTotal number of flavors you want to try at a frozen yogurt shop = 65<br \/>\nNumber of flavors you have tried out of them = 10<\/p>\n<p>Explanation:<br \/>\nNumber of flavors left = Total number of flavors you want to try at a frozen yogurt shop &#8211; Number of flavors you have tried out of them<br \/>\n= 65 &#8211; 10<br \/>\n= 55<br \/>\nHence,\u00a0 Number of flavors left = 55.<\/p>\n<h3><a id=\"Mental_Math:_10_Less_Practice_8.2\"><\/a>Mental Math: 10 Less Practice 8.2<\/h3>\n<p>Use mental math.<\/p>\n<p>Question 1.<br \/>\n12 &#8211; 10 = __________<br \/>\nAnswer:<br \/>\n12 &#8211; 10 = 2.<\/p>\n<p>Explanation:<br \/>\nIn this case, 12 is minuend and 10 is subtrahend.<br \/>\nNow subtract this two:<br \/>\n12 &#8211; 10 = 2.<br \/>\nHence, Difference = 2.<\/p>\n<p>Question 2.<br \/>\n49 &#8211; 10 = __________<br \/>\nAnswer:<br \/>\n49 &#8211; 10 = 39.<\/p>\n<p>Explanation:<br \/>\nIn this case, 49 is minuend and 10 is subtrahend.<br \/>\nNow subtract this two:<br \/>\n49 &#8211; 10 = 39.<br \/>\nHence, Difference = 39.<\/p>\n<p>Question 3.<br \/>\n37 &#8211; 10 = __________<br \/>\nAnswer:<br \/>\n37 &#8211; 10 = 27.<\/p>\n<p>Explanation:<br \/>\nIn this case, 37 is minuend and 10 is subtrahend.<br \/>\nNow subtract this two:<br \/>\n37 &#8211; 10 = 27.<br \/>\nHence, Difference = 27.<\/p>\n<p>Question 4.<br \/>\n26 &#8211; 10 = __________<br \/>\nAnswer:<br \/>\n26 &#8211; 10 = 16.<\/p>\n<p>Explanation:<br \/>\nIn this case, 26 is minuend and 10 is subtrahend.<br \/>\nNow subtract this two:<br \/>\n26 &#8211; 10 = 16.<br \/>\nHence, Difference = 16.<\/p>\n<p>Question 5.<br \/>\n40 &#8211; 10 = __________<br \/>\nAnswer:<br \/>\n40 &#8211; 10 = 30.<\/p>\n<p>Explanation:<br \/>\nIn this case, 40 is minuend and 10 is subtrahend.<br \/>\nNow subtract this two:<br \/>\n40 &#8211; 10 = 30.<br \/>\nHence, Difference = 30.<\/p>\n<p>Question 6.<br \/>\n62 &#8211; 10 = __________<br \/>\nAnswer:<br \/>\n62 &#8211; 10 = 52.<\/p>\n<p>Explanation:<br \/>\nIn this case, 62 is minuend and 10 is subtrahend.<br \/>\nNow subtract this two:<br \/>\n62 &#8211; 10 = 52<br \/>\nHence, Difference = 52.<\/p>\n<p>Question 7.<br \/>\n88 &#8211; 10 = __________<br \/>\nAnswer:<br \/>\n88 &#8211; 10 = 78.<\/p>\n<p>Explanation:<br \/>\nIn this case, 88 is minuend and 10 is subtrahend.<br \/>\nNow subtract this two:<br \/>\n88 &#8211; 10 = 78.<br \/>\nHence, Difference =78.<\/p>\n<p>Question 8.<br \/>\n91 &#8211; 10 = __________<br \/>\nAnswer:<br \/>\n91 &#8211; 10 = 81.<\/p>\n<p>Explanation:<br \/>\nIn this case, 91 is minuend and 10 is subtrahend.<br \/>\nNow subtract this two:<br \/>\n91 &#8211; 10 = 81.<br \/>\nHence, Difference = 81.<\/p>\n<p>Question 9.<br \/>\n54 &#8211; 10 = __________<br \/>\nAnswer:<br \/>\n54 &#8211; 10 = 44<\/p>\n<p>Explanation:<br \/>\nIn this case, 54 is minuend and 10 is subtrahend.<br \/>\nNow subtract this two:<br \/>\n54 &#8211; 10 = 44.<br \/>\nHence, Difference = 44.<\/p>\n<p>Question 10.<br \/>\n76 &#8211; 10 = __________<br \/>\nAnswer:<br \/>\n76 &#8211; 10 = 66.<\/p>\n<p>Explanation:<br \/>\nIn this case, 76 is minuend and 10 is subtrahend.<br \/>\nNow subtract this two:<br \/>\n76 &#8211; 10 = 66.<br \/>\nHence, Difference = 66.<\/p>\n<p>Question 11.<br \/>\n__________ &#8211; 10 = 15<br \/>\nAnswer:<br \/>\n25 &#8211; 10 = 15<\/p>\n<p>Explanation:<br \/>\nIn this case, Missing number\u00a0 is minuend and 10 is subtrahend.<br \/>\nLet missing number be X.<br \/>\nSum is given = 15.<br \/>\nNow subtract :<br \/>\nX &#8211; 10 = 15<br \/>\nX = 15 + 10<br \/>\nX = 25.<br \/>\nHence, Equation is 25 &#8211; 10 = 15.<\/p>\n<p>Question 12.<br \/>\n__________ &#8211; 10 = 77<br \/>\nAnswer:<br \/>\n87 &#8211; 10 = 77<\/p>\n<p>Explanation:<br \/>\nIn this case, Missing number is minuend and 10 is subtrahend.<br \/>\nLet missing number be X.<br \/>\nSum is given = 77.<br \/>\nNow subtract :<br \/>\nX &#8211; 10 = 77<br \/>\nX = 77 + 10<br \/>\nX = 87.<br \/>\nHence, Equation is 87 &#8211; 10 = 77.<\/p>\n<p>Question 13.<br \/>\n__________ &#8211; 10 = 34<br \/>\nAnswer:<br \/>\n44 &#8211; 10 = 34<\/p>\n<p>Explanation:<br \/>\nIn this case, Missing number is minuend and 10 is subtrahend.<br \/>\nLet missing number be X.<br \/>\nSum is given = 34.<br \/>\nNow subtract :<br \/>\nX &#8211; 10 = 34<br \/>\nX = 34 + 10<br \/>\nX = 44.<br \/>\nHence, Equation is 44 &#8211; 10 = 34.<\/p>\n<p>Question 14.<br \/>\n__________ &#8211; 10 = 53<br \/>\nAnswer:<br \/>\n63 &#8211; 10 = 53.<\/p>\n<p>Explanation:<br \/>\nIn this case, Missing number is minuend and 10 is subtrahend.<br \/>\nLet missing number be X.<br \/>\nSum is given = 53.<br \/>\nNow subtract :<br \/>\nX &#8211; 10 = 53<br \/>\nX = 53 + 10<br \/>\nX = 63.<br \/>\nHence, Equation is 63 &#8211; 10 = 53.<\/p>\n<p>Question 15.<br \/>\n<strong>YOU BE THE TEACHER<\/strong><br \/>\nIs Descartes correct? Explain.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26866\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-11.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 8 Add and Subtract Tens 11\" width=\"446\" height=\"152\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-11.png 446w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-11-300x102.png 300w\" sizes=\"(max-width: 446px) 100vw, 446px\" \/><br \/>\nAnswer:<br \/>\n40 &#8211; 10 = 30<\/p>\n<p>Explanation:<br \/>\nIn this case, 40 is minuend and 10 is subtrahend.<br \/>\nNow subtract this two:<br \/>\n40 &#8211; 10 = 30.<br \/>\nDifference = 30.<br \/>\nTherefore, Descartes answer 50 is incorrect because he did not subtract the numbers instead he added the number.<\/p>\n<p>Question 16.<br \/>\n<strong>Modeling Real Life<\/strong><br \/>\nThere are 99 levels in a video game. You complete 10 of them. How many are left?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26865\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-12.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 8 Add and Subtract Tens 12\" width=\"97\" height=\"74\" \/><\/p>\n<p>____________ levels<\/p>\n<p>Answer:<br \/>\nNumber of games left = 89.<\/p>\n<p>Given:<br \/>\nTotal number of levels in a video game = 99<br \/>\nNumber of games I have completed out of them = 10<\/p>\n<p>Explanation:<br \/>\nNumber of games left = Total number of levels in a video game &#8211; Number of games I have completed out of them<br \/>\n= 99 &#8211; 10<br \/>\n= 89<br \/>\nHence, Number of games left = 89.<\/p>\n<p><strong>Review &amp; Refresh<\/strong><\/p>\n<p>Question 17.<br \/>\nA group of students are at the arcade. 4 of them leave. There are 5 left. How many students were there to start?<\/p>\n<p>________ students<\/p>\n<p>Answer:<br \/>\nTotal number of students were there to start = 9.<\/p>\n<p>Given:<br \/>\nNumber of students leave = 4<br \/>\nNumber of students left = 5<\/p>\n<p>Explanation:<br \/>\nTotal number of students were there to start = Number of students leave + Number of students left<br \/>\n= 4 + 5<br \/>\n= 9<br \/>\nHence, total number of students were there to start = 9.<\/p>\n<h3><a id=\"Lesson_8.3_Add_Tens\"><\/a>Lesson 8.3 Add Tens<\/h3>\n<p><strong>Explore and Grow<\/strong><\/p>\n<p>Model each problem. How are the problems alike? How are they different?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26887\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-13.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 8 Add and Subtract Tens 13\" width=\"135\" height=\"91\" \/><\/p>\n<p>3 + 2 = _______<\/p>\n<p>30 + 20 = _______<br \/>\nAnswer:<br \/>\n3 + 2 = 5.<br \/>\n30 + 20 = 50.<\/p>\n<p>Explanation:<br \/>\nA number that is added to another number is known as an addend.<br \/>\n1. In this case, 3 and 2 are the addends.<br \/>\nSum is the result of adding two numbers.<br \/>\n3 + 2 = 5.<br \/>\n2. In this case, 30 and 20 are the addends.<br \/>\nSum is the result of adding two numbers.<br \/>\n30 + 20 = 50.<br \/>\nHence, the problem is alike in its addition process and different in its sum.<\/p>\n<p><strong>Show and Grow<\/strong><\/p>\n<p>Question 1.<br \/>\n40 + 50 = ?<br \/>\n____________ tens + ____________ tens = ____________ tens<br \/>\nSo, 40 + 50 = ____________ .<\/p>\n<p>Answer:<br \/>\n40 + 50 = 90.<\/p>\n<p>Explanation:<br \/>\nPlace value\u00a0is the\u00a0value of each digit in a number.<br \/>\n4 value in 40 = 4 tens<br \/>\n5 value in 50 = 5 tens<br \/>\nAdd the two numbers:<br \/>\n=&gt; 4 tens + 5 tens = 9 tens.<br \/>\nSo, 40 + 50 = 90.<\/p>\n<p>Question 2.<br \/>\n30 + 30 = ?<br \/>\n____________ tens + ____________ tens = ____________ tens<br \/>\nSo, 30 + 30 = ____________ .<\/p>\n<p>Answer:<br \/>\n30 + 30 = 60.<\/p>\n<p>Explanation:<br \/>\nPlace value\u00a0is the\u00a0value of each digit in a number.<br \/>\n3 value in 30 = 3 tens<br \/>\n3 value in 30 = 3 tens<br \/>\nAdd the two numbers:<br \/>\n3 tens + 3 tens = 6 tens<br \/>\nSo, 30 + 30 = 60.<\/p>\n<p><strong>Apply and Grow: Practice<\/strong><\/p>\n<p>Question 3.<br \/>\n20 + 40 = ?<br \/>\n____________ tens + ____________ tens = ____________ tens<br \/>\nSo, 20 + 40 = ____________ .<br \/>\nAnswer:<br \/>\n20 + 40 = 60<\/p>\n<p>Explanation:<br \/>\nPlace value\u00a0is the\u00a0value of each digit in a number.<br \/>\n2 value in 20 = 2 tens<br \/>\n4 value in 40 = 4 tens<br \/>\nAdd the two numbers:<br \/>\n2 tens + 4 tens = 6 tens<br \/>\nSo, 20 + 40 = 60.<\/p>\n<p>Question 4.<br \/>\n50 + 30 = ?<br \/>\n____________ tens + ____________ tens = ____________ tens<br \/>\nSo, 50 + 30 = ____________ .<br \/>\nAnswer:<br \/>\n50 + 30 = 80.<\/p>\n<p>Explanation:<br \/>\nPlace value\u00a0is the\u00a0value of each digit in a number.<br \/>\n5 value in 50 = 5 tens<br \/>\n3 value in 30 = 3 tens<br \/>\nAdd the two numbers:<br \/>\n5 tens + 3 tens = 8 tens<br \/>\nSo, 50 + 30 = 80.<\/p>\n<p>Question 5.<br \/>\n40 + 10 = _________<br \/>\nAnswer:<br \/>\n40 + 10 = 50.<\/p>\n<p>Explanation:<br \/>\nPlace value\u00a0is the\u00a0value of each digit in a number.<br \/>\n4 value in 40 = 4 tens<br \/>\n1 value in 10 = 1 tens<br \/>\nAdd the two numbers:<br \/>\n4 tens + 1 tens = 5 tens<br \/>\nSo, 40 + 10 = 50.<\/p>\n<p>Question 6.<br \/>\n70 + 20 = _________<br \/>\nAnswer:<br \/>\n70 + 20 = 90.<\/p>\n<p>Explanation:<br \/>\nPlace value\u00a0is the\u00a0value of each digit in a number.<br \/>\n7 value in 70 = 7 tens<br \/>\n2 value in 20 = 2 tens<br \/>\nAdd the two numbers:<br \/>\n7 tens + 2 tens = 9 tens<br \/>\nSo, 70 + 20 = 90..<\/p>\n<p>Question 7.<br \/>\n30 + 40 = _________<br \/>\nAnswer:<br \/>\n30 + 40 = 70.<\/p>\n<p>Explanation:<br \/>\nPlace value\u00a0is the\u00a0value of each digit in a number.<br \/>\n3 value in 30 = 3 tens<br \/>\n4 value in 40 = 4 tens<br \/>\nAdd the two numbers:<br \/>\n3 tens + 4 tens = 7 tens<br \/>\nSo, 30 + 40 = 70.<\/p>\n<p>Question 8.<br \/>\n20 + 60 = __________<br \/>\nAnswer:<br \/>\n20 + 60 = 80.<\/p>\n<p>Explanation:<br \/>\nPlace value\u00a0is the\u00a0value of each digit in a number.<br \/>\n2 value in 20 = 2 tens<br \/>\n6 value in 60 = 6 tens<br \/>\nAdd the two numbers:<br \/>\n2 tens + 6 tens = 8 tens<br \/>\nSo, 20 + 60 = 80.<\/p>\n<p>Question 9.<br \/>\n_________ + 10 = 40<br \/>\nAnswer:<br \/>\n30 + 10 = 40.<\/p>\n<p>Explanation:<br \/>\nLet the first addend be X.<br \/>\nSecond addend given= 10<br \/>\nSum is given = 40<br \/>\nNow add :<br \/>\nX + 10 = 40<br \/>\nX = 40 &#8211; 10<br \/>\nx = 30.<br \/>\nHence, Equation is 30 + 10 = 40.<\/p>\n<p>Question 10.<br \/>\n_________ + 60 = 90<br \/>\nAnswer:<br \/>\n30 + 60 = 90.<\/p>\n<p>Explanation:<br \/>\nLet the first addend be X.<br \/>\nSecond addend given = 60<br \/>\nSum is given = 90<br \/>\nNow add :<br \/>\nX + 60 = 90<br \/>\nX = 90 &#8211; 60<br \/>\nX = 30.<br \/>\nHence, Equation is 30 + 60 = 90.<\/p>\n<p>Question 11.<br \/>\n<strong>DIG DEEPER!<\/strong><br \/>\nWhich choices match the model?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26886\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-14.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 8 Add and Subtract Tens 14\" width=\"75\" height=\"85\" \/><br \/>\n50\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a020 + 30<br \/>\n2 tens + 3 ones\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 1 ten + 4 tens<\/p>\n<p>Answer:<br \/>\n1 ten + 4 tens = 5 tens.<\/p>\n<p>Explanation:<br \/>\nIn the above picture, 5 lines are given.<br \/>\nConsidered each line value as 10.<br \/>\nHere, two addends are given in each choice:<br \/>\nNow add this two :<br \/>\n1. 50<br \/>\n2. 20 + 30 = 50<br \/>\n3. 2 tens + 3 ones = 20 + 3=23<br \/>\n4. 1 ten + 4 tens = 5 tens<br \/>\nHence, 4th choice matches the model because five lines of each value 10 = 50 not others as addition of two numbers it did not refer in the model.<\/p>\n<p><strong>Think and Grow: Modeling Real Life<\/strong><\/p>\n<p>One tray has 20 meatballs. Another tray has the same number of meatballs. How many meatballs are there in all?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26885\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-15.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 8 Add and Subtract Tens 15\" width=\"155\" height=\"88\" \/><br \/>\nModel:<\/p>\n<p>Addition equation:<\/p>\n<p>__________ meatballs<\/p>\n<p>Answer:<br \/>\nTotal number of meatballs are there in all = 40.<\/p>\n<p>Given:<br \/>\nNumber of meatballs one tray has = 20<br \/>\nNumber of meatballs same another tray has = 20<br \/>\nExplanation:<br \/>\nTotal number of meatballs are there in all =\u00a0 Number of meatballs one tray has &#8211; Number of meatballs same another tray has<br \/>\n= 20 + 20<br \/>\n= 40<br \/>\nHence, Total number of meatballs are there in all = 40.<\/p>\n<p><strong>Show and Grow<\/strong><\/p>\n<p>Question 12.<br \/>\nOne box has 40 bags of pretzels. Another box has the same number of bags. How many bags are there in all?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26884\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-16.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 8 Add and Subtract Tens 16\" width=\"159\" height=\"105\" \/><br \/>\nModel:<\/p>\n<p>Addition equation:<\/p>\n<p>__________ bags<\/p>\n<p>Answer:<br \/>\nTotal number of bags are there in all = 80.<\/p>\n<p>Given:<br \/>\nNumber of bags of pretzels one box has = 40<br \/>\nNumber of bags of pretzels another box has = 40<\/p>\n<p>Explanation:<br \/>\nTotal number of bags are there in all = Number of bags of pretzels one box has + Number of bags of pretzels another box has<br \/>\n= 40 + 40<br \/>\n= 80.<br \/>\nHence, Total number of bags are there in all = 80.<\/p>\n<h3><a id=\"Add_Tens_Practice_8.3\"><\/a>Add Tens Practice 8.3<\/h3>\n<p>Question 1.<br \/>\n20 + 70 = ?<br \/>\n____________ tens + ____________ tens = ____________ tens<br \/>\nSo, 20 + 70 = ____________ .<br \/>\nAnswer:<br \/>\n2tens + 7tens = 9tens<br \/>\n20 + 70 = 90.<\/p>\n<p>Explanation:<br \/>\nHere place value of 2 and 7 are considered.<br \/>\nAdd the two numbers.<br \/>\n2tens + 7tens = 9tens<br \/>\n20 + 70 =\u00a090.<\/p>\n<p>Question 2.<br \/>\n50 + 30 = ?<br \/>\n____________ tens + ____________ tens = ____________ tens<br \/>\nSo, 50 + 30 = ____________ .<br \/>\nAnswer:<br \/>\n5tens + 3tens = 8tens<br \/>\n50 + 30 = 80.<\/p>\n<p>Explanation:<br \/>\nHere place value of 2 and 7 are considered.<br \/>\nAdd the two numbers.<br \/>\n5tens + 3tens = 8tens<br \/>\n50 + 30 = 80.<\/p>\n<p>Question 3.<br \/>\n60 + 20 = ___________<br \/>\nAnswer:<br \/>\n6tens + 2tens = 8tens.<br \/>\n60 + 20 = 80.<\/p>\n<p>Explanation:<br \/>\nHere place value of 2 and 7 are considered.<br \/>\nAdd the two numbers.<br \/>\n6tens + 2tens = 8tens.<br \/>\n60 + 20 = 80.<\/p>\n<p>Question 4.<br \/>\n40 + 40 = ____________<br \/>\nAnswer:<br \/>\n4tens + 4tens = 8tens.<br \/>\n40 + 40 = 80.<\/p>\n<p>Explanation:<br \/>\nHere place value of 4 and 4 are considered.<br \/>\nAdd the two numbers.<br \/>\n4tens + 4tens = 8tens.<br \/>\n40 + 40 = 80.<\/p>\n<p>Question 5.<br \/>\n__________ + 40 = 50<br \/>\nAnswer:<br \/>\n1 tens + 4 tens = 5 tens.<br \/>\n10 + 40 = 50.<\/p>\n<p>Explanation:<br \/>\nLet the missing number be X.<br \/>\nAdd the numbers now.<br \/>\nX + 40 = 50<br \/>\nX = 50 &#8211; 40<br \/>\nX = 10<br \/>\n1 tens + 4 tens = 5 tens.<br \/>\n10 + 40 = 50.<\/p>\n<p>Question 6.<br \/>\n___________ + 30 = 60<br \/>\nAnswer:<br \/>\n3 tens + 3 tens = 6 tens.<br \/>\n30 + 30 = 60.<\/p>\n<p>Explanation:<br \/>\nLet the missing number be X.<br \/>\nAdd the numbers now.<br \/>\nX + 30 = 60<br \/>\nX = 60 &#8211; 30<br \/>\nX = 30<br \/>\n3 tens + 3 tens = 6 tens.<br \/>\n30 + 30 = 60.<\/p>\n<p>Question 7.<br \/>\n___________ + 20 = 70<br \/>\nAnswer:<br \/>\n5 tens + 2 tens = 7 tens.<br \/>\n50 + 20 = 70.<\/p>\n<p>Explanation:<br \/>\nLet the missing number be X.<br \/>\nAdd the numbers now.<br \/>\nX + 20 = 70<br \/>\nX = 70 &#8211; 20<br \/>\nX = 50<br \/>\n5 tens + 2 tens = 7 tens.<br \/>\n50 + 20 = 70.<\/p>\n<p>Question 8.<br \/>\n_____________ + 50 = 90<br \/>\nAnswer:<br \/>\n5 tens + 4 tens = 90.<br \/>\n50 + 40 = 90.<\/p>\n<p>Explanation:<br \/>\nLet the missing number be X.<br \/>\nAdd the numbers now.<br \/>\nX + 50 = 90<br \/>\nX = 90 &#8211; 50<br \/>\nX = 40<br \/>\n5 tens + 4 tens = 90.<br \/>\n50 + 40 = 90.<\/p>\n<p>Question 9.<br \/>\n<strong>DIG DEEPER!<\/strong><br \/>\nWhich choices match the model?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26883\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-17.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 8 Add and Subtract Tens 17\" width=\"103\" height=\"83\" \/><br \/>\n3 tens + 4 ones\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a05 tens + 2 tens<br \/>\n60\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 30 + 40<br \/>\nAnswer:<br \/>\n3 tens + 4 tens = 7 tens<br \/>\n5 tens + 2 tens = 7 tens<\/p>\n<p>Explanation:<br \/>\n1. 3 tens + 4 tens = 7 tens<br \/>\n2. 60<br \/>\n3. 5 tens + 2 tens = 7 tens<br \/>\n4. 30 + 40 = 70<br \/>\nHence, 2nd and 3rd choice matches the model because five lines of each value 10\u00a0 x 7 = 70 not others as addition of two numbers it did not refer in the model.<\/p>\n<p>Question 10.<br \/>\n<strong>Modeling Real Life<\/strong><br \/>\nOne magic set has 30 pieces. Another set has the same number of pieces. How many pieces are there in all?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26882\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-18.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 8 Add and Subtract Tens 18\" width=\"99\" height=\"95\" \/><\/p>\n<p>_____________ pieces<br \/>\nAnswer:<br \/>\nTotal Number of\u00a0 pieces are there in all = 60.<\/p>\n<p>Explanation:<br \/>\nNumber\u00a0 of pieces magic sets has = 30<br \/>\nNumber of\u00a0 pieces another magic sets has same\u00a0 = 30<br \/>\nTotal Number of\u00a0 pieces are there in all = Number\u00a0 of pieces magic sets has + Number of\u00a0 pieces another magic sets has same<br \/>\n= 30 + 30<br \/>\n= 60.<br \/>\nHence, Total Number of\u00a0 pieces are there in all = 60.<\/p>\n<p><strong>Review &amp; Refresh<\/strong><\/p>\n<p>Question 11.<br \/>\n__________ = 6 + 5<br \/>\nAnswer:<br \/>\n11 = 6 + 5<\/p>\n<p>Explanation:<br \/>\nLet the sum of addends 6 and 5 be X.<br \/>\nadd the two numbers.<br \/>\nX = 6 + 5<br \/>\nX = 11.<br \/>\nHence, 11 = 6 + 5.<\/p>\n<p>Question 12.<br \/>\n__________ = 3 + 17<br \/>\nAnswer:<br \/>\n20 = 3 + 17<\/p>\n<p>Explanation:<br \/>\nLet the sum of addends 3 and 17 be X.<br \/>\nAdd the two numbers.<br \/>\nX = 3 + 17<br \/>\nX = 20.<br \/>\nHence, 20 = 3 + 17.<\/p>\n<p>Question 13.<br \/>\n__________ = 11 + 5<br \/>\nAnswer:<br \/>\n16 = 11 + 5.<\/p>\n<p>Explanation:<br \/>\nLet the sum of addends 11 and 5 be X.<br \/>\nAdd the two numbers.<br \/>\nX = 11 + 5<br \/>\nX = 16.<br \/>\nHence, 16 = 11 + 5.<\/p>\n<p>Question 14.<br \/>\n__________ = 5 + 9<br \/>\nAnswer:<br \/>\n14 = 5 + 9.<\/p>\n<p>Explanation:<br \/>\nLet the sum of addends 5 and 9 be X.<br \/>\nAdd the two numbers.<br \/>\nX = 5 + 9<br \/>\nX = 14.<br \/>\nHence, 14 = 5 + 9.<\/p>\n<h3><a id=\"Lesson_8.4_Add_Tens_Using_a_Number_Line\"><\/a>Lesson 8.4 Add Tens Using a Number Line<\/h3>\n<p><strong>Explore and Grow<\/strong><\/p>\n<p>Write the missing numbers. How do the hops help you solve?<\/p>\n<p>30 + 20 = _________<\/p>\n<p><img loading=\"lazy\" class=\"alignnone size-full wp-image-26905\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-19.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 8 Add and Subtract Tens 19\" width=\"433\" height=\"158\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-19.png 433w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-19-300x109.png 300w\" sizes=\"(max-width: 433px) 100vw, 433px\" \/><\/p>\n<p>Answer:<br \/>\n30 + 20 = 50.<\/p>\n<p>Explanation:<br \/>\nIn math, a number line can be defined as a straight line with numbers placed at equal intervals or segments along its length.<br \/>\nHere, in the above picture the interval is calculated and added.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33434\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.4-Add-Tens-Using-a-Number-Line-1-1.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Lesson 8.4-Add-Tens-Using-a-Number-Line-\" width=\"511\" height=\"233\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.4-Add-Tens-Using-a-Number-Line-1-1.png 511w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.4-Add-Tens-Using-a-Number-Line-1-1-300x137.png 300w\" sizes=\"(max-width: 511px) 100vw, 511px\" \/><br \/>\n30 + 10 + 10<br \/>\n= 40 + 10<br \/>\n= 50 .<br \/>\nHence, 30 + 20 = 50.<\/p>\n<p><strong>Show and Grow<\/strong><\/p>\n<p>Question 1.<br \/>\n50 + 40 = __________<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26904\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-20.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 8 Add and Subtract Tens 20\" width=\"427\" height=\"42\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-20.png 427w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-20-300x30.png 300w\" sizes=\"(max-width: 427px) 100vw, 427px\" \/><br \/>\nAnswer:<br \/>\n50 + 40 = 90.<\/p>\n<p>Explanation:<br \/>\nOn the number line, give the interval of 10 for 4 times\u00a0 and add them to given number.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33435\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.4-Add-Tens-Using-a-Number-Line-Show-and-Grow1-1.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Lesson 8.4-Add-Tens-Using-a-Number-Line-Show and Grow1\" width=\"521\" height=\"134\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.4-Add-Tens-Using-a-Number-Line-Show-and-Grow1-1.png 521w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.4-Add-Tens-Using-a-Number-Line-Show-and-Grow1-1-300x77.png 300w\" sizes=\"(max-width: 521px) 100vw, 521px\" \/><br \/>\nHence, 50 + 40 = 90.<\/p>\n<p>Question 2.<br \/>\n60 + 20 = _____________<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26903\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-21.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 8 Add and Subtract Tens 21\" width=\"424\" height=\"43\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-21.png 424w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-21-300x30.png 300w\" sizes=\"(max-width: 424px) 100vw, 424px\" \/><br \/>\nAnswer:<br \/>\n60 + 20 = 80<\/p>\n<p>Explanation:<br \/>\nOn the number line, give the interval of 10 for 2 times and add them to given number.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33436\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.4-Add-Tens-Using-a-Number-Line-Show-and-Grow2-1.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Lesson 8.4-Add-Tens-Using-a-Number-Line-Show and Grow2\" width=\"522\" height=\"168\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.4-Add-Tens-Using-a-Number-Line-Show-and-Grow2-1.png 522w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.4-Add-Tens-Using-a-Number-Line-Show-and-Grow2-1-300x97.png 300w\" sizes=\"(max-width: 522px) 100vw, 522px\" \/><br \/>\nHence, 60 + 20 = 80<\/p>\n<p><strong>Apply and Grow: Practice<\/strong><\/p>\n<p>Question 3.<br \/>\n40 + 20 = _________<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26902\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-22.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 8 Add and Subtract Tens 22\" width=\"423\" height=\"42\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-22.png 423w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-22-300x30.png 300w\" sizes=\"(max-width: 423px) 100vw, 423px\" \/><br \/>\nAnswer:<br \/>\n40 + 20 = 60.<\/p>\n<p>Explanation:<br \/>\nOn the number line, give the interval of 10 for 2 times and add them to given number.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33440\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.4-Add-Tens-Using-a-Number-Line-Show-and-Grow3-1.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Lesson 8.4-Add-Tens-Using-a-Number-Line-Show and Grow3\" width=\"504\" height=\"133\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.4-Add-Tens-Using-a-Number-Line-Show-and-Grow3-1.png 504w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.4-Add-Tens-Using-a-Number-Line-Show-and-Grow3-1-300x79.png 300w\" sizes=\"(max-width: 504px) 100vw, 504px\" \/><br \/>\nHence, 40 + 20 = 60.<\/p>\n<p>Question 4.<br \/>\n50 + 30 = ___________<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26901\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-23.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 8 Add and Subtract Tens 23\" width=\"428\" height=\"30\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-23.png 428w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-23-300x21.png 300w\" sizes=\"(max-width: 428px) 100vw, 428px\" \/><br \/>\nAnswer:<br \/>\n50 + 30 = 80.<\/p>\n<p>Explanation:<br \/>\nOn the number line, give the interval of 10 for 3 times and add them to given number.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33438\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.4-Add-Tens-Using-a-Number-Line-Show-and-Grow4-1.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Lesson 8.4-Add-Tens-Using-a-Number-Line-Show and Grow4\" width=\"503\" height=\"136\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.4-Add-Tens-Using-a-Number-Line-Show-and-Grow4-1.png 503w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.4-Add-Tens-Using-a-Number-Line-Show-and-Grow4-1-300x81.png 300w\" sizes=\"(max-width: 503px) 100vw, 503px\" \/><br \/>\nHence, 50 + 30 = 80.<\/p>\n<p>Question 5.<br \/>\n60 + 40 = __________<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26901\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-23.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 8 Add and Subtract Tens 23\" width=\"428\" height=\"30\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-23.png 428w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-23-300x21.png 300w\" sizes=\"(max-width: 428px) 100vw, 428px\" \/><br \/>\nAnswer:<br \/>\n60 + 40 = 100.<\/p>\n<p>Explanation:<br \/>\nOn the number line, give the interval of 10 for 4 times and add them to given number.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33441\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.4-Add-Tens-Using-a-Number-Line-Show-and-Grow5-1.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Lesson 8.4-Add-Tens-Using-a-Number-Line-Show and Grow5\" width=\"585\" height=\"155\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.4-Add-Tens-Using-a-Number-Line-Show-and-Grow5-1.png 585w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.4-Add-Tens-Using-a-Number-Line-Show-and-Grow5-1-300x79.png 300w\" sizes=\"(max-width: 585px) 100vw, 585px\" \/><\/p>\n<p>Hence, 60 + 40 = 100.<\/p>\n<p>Question 6.<br \/>\n20 + 50 = ___________<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26901\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-23.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 8 Add and Subtract Tens 23\" width=\"428\" height=\"30\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-23.png 428w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-23-300x21.png 300w\" sizes=\"(max-width: 428px) 100vw, 428px\" \/><br \/>\nAnswer:<br \/>\n20 + 50 = 70.<\/p>\n<p>Explanation:<br \/>\nOn the number line, give the interval of 10 for 5 times and add them to given number.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33442\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.4-Add-Tens-Using-a-Number-Line-Show-and-Grow6-1.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Lesson 8.4-Add-Tens-Using-a-Number-Line-Show and Grow6\" width=\"599\" height=\"155\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.4-Add-Tens-Using-a-Number-Line-Show-and-Grow6-1.png 599w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.4-Add-Tens-Using-a-Number-Line-Show-and-Grow6-1-300x78.png 300w\" sizes=\"(max-width: 599px) 100vw, 599px\" \/><br \/>\nHence, 20 + 50 = 70.<\/p>\n<p>Question 7.<br \/>\n<strong>MP Structure<\/strong><br \/>\nWrite an equation that matches the number line.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26900\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-24.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 8 Add and Subtract Tens 24\" width=\"253\" height=\"130\" \/><br \/>\nAnswer:<br \/>\nEquation: 70 + 10 +10 = 90.<\/p>\n<p>Explanation:<br \/>\nOn the number line, give the interval of 10 for 2 times and add them to given number.<\/p>\n<p><img src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-24.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 8 Add and Subtract Tens 24\" \/><\/p>\n<p>Equation:<br \/>\n70 + 10 +10<br \/>\n= 80 + 10<br \/>\n= 90.<br \/>\nHence, Equation: 70 + 10 +10 = 90.<\/p>\n<p><strong>Think and Grow: Modeling Real Life<\/strong><\/p>\n<p>You have 20 cans. You collect 20 more cans. Your friend collects 45 cans in all. Who collects more cans?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26899\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-25.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 8 Add and Subtract Tens 25\" width=\"140\" height=\"99\" \/><br \/>\nModel:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26898\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-26.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 8 Add and Subtract Tens 26\" width=\"429\" height=\"27\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-26.png 429w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-26-300x19.png 300w\" sizes=\"(max-width: 429px) 100vw, 429px\" \/><br \/>\nAddition equation:<br \/>\nCompare: ___________ \u25cb ___________<br \/>\nWho collects more cans?\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 You\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 Friend<\/p>\n<p>Answer:<br \/>\nMy friend collects\u00a0 5 more cans than me .<\/p>\n<p>Given:<br \/>\nNumber of cans I have = 20<br \/>\nNumber of cans I have collected more = 20<\/p>\n<p>Explanation:<br \/>\nTotal number of cans I have in all = Number of cans I have + Number of cans I have collected more<br \/>\n20 + 20 = 40.<br \/>\nTotal number of cans my friend has = 45<br \/>\nDifference in cans collection = Total number of cans my friend has &#8211; Total number of cans I have in all<br \/>\n= 45 &#8211; 40<br \/>\n= 5<\/p>\n<p>Comparison:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33443\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.4-Add-Tens-Using-a-Number-Line-Think-and-Grow-Modeling-Real-Life-1.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Lesson 8.4-Add-Tens-Using-a-Number-Line-Think and Grow-Modeling Real Life\" width=\"157\" height=\"57\" \/><\/p>\n<p>Hence, my friend collects\u00a0 5 more cans than me .<\/p>\n<p><strong>Show and Grow<\/strong><\/p>\n<p>Question 8.<br \/>\nYour class makes 62 paper airplanes. Your friend\u2019s class makes 30 small airplanes and 30 large airplanes. Whose class makes more airplanes?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26897\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-27.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 8 Add and Subtract Tens 27\" width=\"80\" height=\"135\" \/><br \/>\nModel:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26896\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-28.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 8 Add and Subtract Tens 28\" width=\"424\" height=\"24\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-28.png 424w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-28-300x17.png 300w\" sizes=\"(max-width: 424px) 100vw, 424px\" \/><br \/>\nAddition equation:<br \/>\nCompare: ___________ \u25cb ___________<br \/>\nWhose class makes more airplanes?<br \/>\nYour class\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0Friend&#8217;s class<\/p>\n<p>Answer:<br \/>\nTotal number of paper airplanes I make are 2 more than my friends paper making airplanes.<\/p>\n<p>Given:<br \/>\nTotal number of paper airplanes I make = 62<br \/>\nNumber of paper small airplanes my friend&#8217;s class makes = 30<br \/>\nNumber of paper large airplanes my friend&#8217;s class makes\u00a0 = 30<\/p>\n<p>Explanation:<br \/>\nTotal number of airplanes my friend&#8217;s class makes = Number of paper small airplanes my friend&#8217;s class makes + Number of paper large airplanes my friend&#8217;s class makes<br \/>\n= 30 + 30<br \/>\n= 60<br \/>\nNumber of airplanes who makes more = Total number of paper airplanes class I makes &#8211; Total number of airplanes my friend&#8217;s class makes<br \/>\n=62 &#8211; 60<br \/>\n= 2<\/p>\n<p>Comparison:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33445\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.4-Add-Tens-Using-a-Number-Line-Think-and-Grow-Modeling-Real-Life-Show-and-Grow8-1.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Lesson 8.4-Add-Tens-Using-a-Number-Line-Think and Grow-Modeling Real Life-Show and Grow8\" width=\"160\" height=\"69\" \/><br \/>\nHence, Total number of paper airplanes I make\u00a0 2 more than my friends paper making airplanes.<\/p>\n<h3><a id=\"Add_Tens_Using_a_Number_Line_Practice_8.4\"><\/a>Add Tens Using a Number Line Practice 8.4<\/h3>\n<p>Question 1.<br \/>\n60 + 30 = __________<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26895\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-29.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 8 Add and Subtract Tens 29\" width=\"424\" height=\"43\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-29.png 424w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-29-300x30.png 300w\" sizes=\"(max-width: 424px) 100vw, 424px\" \/><br \/>\nAnswer:<br \/>\n60 + 30 = 90.<\/p>\n<p>Explanation:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33477\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.4-Add-Tens-Using-a-Number-Line-Add-Tens-Using-a-Number-Line-Practice-8.4-1.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Lesson 8.4-Add-Tens-Using-a-Number-Line-Add-Tens-Using-a-Number-Line-Practice- 8.4-1\" width=\"505\" height=\"161\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.4-Add-Tens-Using-a-Number-Line-Add-Tens-Using-a-Number-Line-Practice-8.4-1.png 505w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.4-Add-Tens-Using-a-Number-Line-Add-Tens-Using-a-Number-Line-Practice-8.4-1-300x96.png 300w\" sizes=\"(max-width: 505px) 100vw, 505px\" \/><br \/>\nEquation:<br \/>\n60+ 10 +10 +10<br \/>\n=70 + 10 +10<br \/>\n= 80 + 10<br \/>\n=90.<\/p>\n<p>Question 2.<br \/>\n20 + 20 = __________<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26894\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-30.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 8 Add and Subtract Tens 30\" width=\"423\" height=\"29\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-30.png 423w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-30-300x21.png 300w\" sizes=\"(max-width: 423px) 100vw, 423px\" \/><br \/>\nAnswer:<br \/>\n20 + 10+ 10 = 40.<\/p>\n<p>Explanation:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33478\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.4-Add-Tens-Using-a-Number-Line-Add-Tens-Using-a-Number-Line-Practice-8.4-2.png\" alt=\"\" width=\"503\" height=\"150\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.4-Add-Tens-Using-a-Number-Line-Add-Tens-Using-a-Number-Line-Practice-8.4-2.png 503w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.4-Add-Tens-Using-a-Number-Line-Add-Tens-Using-a-Number-Line-Practice-8.4-2-300x89.png 300w\" sizes=\"(max-width: 503px) 100vw, 503px\" \/><br \/>\nEquation:<br \/>\n20 + 10+ 10<br \/>\n= 30 + 10<br \/>\n= 40.<\/p>\n<p>Question 3.<br \/>\n30 + 70 = __________<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26894\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-30.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 8 Add and Subtract Tens 30\" width=\"423\" height=\"29\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-30.png 423w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-30-300x21.png 300w\" sizes=\"(max-width: 423px) 100vw, 423px\" \/><br \/>\nAnswer:<br \/>\n30 + 70 = 100.<\/p>\n<p>Explanation:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33480\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.4-Add-Tens-Using-a-Number-Line-Add-Tens-Using-a-Number-Line-Practice-8.4-3.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Lesson 8.4-Add-Tens-Using-a-Number-Line-Add-Tens-Using-a-Number-Line-Practice- 8.4-3\" width=\"932\" height=\"175\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.4-Add-Tens-Using-a-Number-Line-Add-Tens-Using-a-Number-Line-Practice-8.4-3.png 932w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.4-Add-Tens-Using-a-Number-Line-Add-Tens-Using-a-Number-Line-Practice-8.4-3-300x56.png 300w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.4-Add-Tens-Using-a-Number-Line-Add-Tens-Using-a-Number-Line-Practice-8.4-3-768x144.png 768w\" sizes=\"(max-width: 932px) 100vw, 932px\" \/><br \/>\nEquation:<br \/>\n30 + 10 + 10+ 10+ 10+ 10+ 10 +10<br \/>\n= 40 + 10+ 10+ 10+ 10+ 10 +10<br \/>\n= 50 +10+ 10+ 10+ 10 +10<br \/>\n= 60\u00a0 +10+ 10+ 10 +10<br \/>\n= 70 + 10 + 10 +10<br \/>\n= 80 + 10 +10<br \/>\n= 90 + 10<br \/>\n= 100.<\/p>\n<p>Question 4.<br \/>\n<strong>MP Structure<\/strong><br \/>\nWrite an equation that matches the number line.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26893\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-31.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 8 Add and Subtract Tens 31\" width=\"422\" height=\"140\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-31.png 422w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-31-300x100.png 300w\" sizes=\"(max-width: 422px) 100vw, 422px\" \/><br \/>\nAnswer:<br \/>\nEquation:<br \/>\n10 + 40 = 50.<\/p>\n<p>Explanation:<br \/>\nThe number line shows the interval of 10 for 4 times.<br \/>\n10 + 10 + 10 + 10 +10<br \/>\n= 20 + 10 + 10 + 10<br \/>\n= 30 + 10 + 10<br \/>\n= 40 + 10<br \/>\n= 50.<\/p>\n<p>Question 5.<br \/>\n<strong>Modeling Real Life<\/strong><br \/>\nYou make 3 snow bricks. Your friend makes 20 small snow bricks and 30 large snow bricks. Who makes more snow bricks?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26892\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-32.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 8 Add and Subtract Tens 32\" width=\"126\" height=\"112\" \/><br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26891\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-33.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 8 Add and Subtract Tens 33\" width=\"422\" height=\"25\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-33.png 422w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-33-300x18.png 300w\" sizes=\"(max-width: 422px) 100vw, 422px\" \/><br \/>\nWho makes more snow bricks?\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 You\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 Friend<br \/>\nAnswer:<br \/>\nMy friend has 47 more snow bricks than me.<\/p>\n<p>Given:<br \/>\nTotal number of snow bricks I have made = 3<br \/>\nNumber of small snow bricks my friend has made = 20<br \/>\nNumber of large snow bricks my friend has made = 30<\/p>\n<p>Explanation:<br \/>\nTotal number of small and large snow bricks my friend has made = Number of small snow bricks my friend has made + Number of large snow bricks my friend has made<br \/>\n= 20 + 30<br \/>\n= 50<br \/>\nNumber of \u00a0snow bricks who makes more = Total number of small and large snow bricks my friend has made &#8211; total number of snow bricks I have made<br \/>\n= 50 &#8211; 3<br \/>\n= 47.<\/p>\n<p>Comparison:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33476\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.4-Add-Tens-Using-a-Number-Line-Think-and-Grow-Modeling-Real-Life-Show-and-Grow5..png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Lesson 8.4-Add-Tens-Using-a-Number-Line-Think and Grow-Modeling Real Life-Show and Grow5.\" width=\"127\" height=\"44\" \/><br \/>\nHence, my friend has 47 more snow bricks than me.<\/p>\n<p><strong>Review &amp; Refresh<\/strong><\/p>\n<p>Question 6.<br \/>\nGet to lo to subtract.<br \/>\n17 &#8211; 8 = ?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26890\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-34.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 8 Add and Subtract Tens 34\" width=\"170\" height=\"146\" \/><br \/>\n17 &#8211; __________ = 10<br \/>\n10 &#8211; __________ = __________<br \/>\nSo, 17 &#8211; 8 = __________ .<br \/>\nAnswer:<br \/>\n17 &#8211; 8 = 9.<\/p>\n<p>Given:<br \/>\n1. 17 &#8211; ____ = 10<br \/>\n<span style=\"font-family: Verdana, Arial, Helvetica, sans-serif; font-size: small;\">Let the missing subtrahend be X.<br \/>\nDifference is given = 10<br \/>\nSubtract the numbers.<br \/>\n17 &#8211; X = 10<br \/>\n17 = 10 + X<br \/>\n17 &#8211; 10 = X<br \/>\n7 = X<br \/>\nEquation: 17 &#8211; 7 = 10.<\/span><\/p>\n<h3><a id=\"Lesson_8.5_Subtract_Tens\"><\/a>Lesson 8.5 Subtract Tens<\/h3>\n<p><strong>Explore and Grow<\/strong><\/p>\n<p>Model each problem. How are the problems alike? How are they different?<\/p>\n<p><img loading=\"lazy\" class=\"alignnone size-full wp-image-26913\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-8-Add-and-Subtract-Tens-35.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 8 Add and Subtract Tens 35\" width=\"166\" height=\"93\" \/><\/p>\n<p>5 &#8211; 2 = ___________<\/p>\n<p>50 &#8211; 20 = ___________<br \/>\nAnswer:<br \/>\n5 &#8211; 2 = 3.<br \/>\n50 &#8211; 20 = 30.<\/p>\n<p>Explanation:<br \/>\nHere, the minuend is 5 and the subtrahend is 2.<b><br \/>\n<\/b>Now, Subtract the two numbers.<br \/>\n5 &#8211; 2 = 3.<br \/>\nHere, the minuend is 50 and the subtrahend is 20.<b><br \/>\n<\/b>Now, Subtract the two numbers.<br \/>\n50 &#8211; 20 = 30.<br \/>\nHence, the two equations are alike in the subtraction process yet different in the answers.<\/p>\n<p><strong>Show and Grow<\/strong><\/p>\n<p>Question 1.<\/p>\n<p>70 &#8211; 30 = ?<br \/>\n____________ tens &#8211; ____________ tens = ____________ tens<br \/>\nSo, 70 &#8211; 30 = ____________ .<br \/>\nAnswer:<br \/>\n7 tens &#8211; 3 tens = 4 tens<br \/>\n70 &#8211; 30 = 40.<\/p>\n<p>Explanation:<br \/>\nPlace value\u00a0is the\u00a0value of each digit in a number.<br \/>\n7 value in 70 =7 tens<br \/>\n3 value in 30 = 3 tens<br \/>\nSubtract the two numbers:<br \/>\n7 tens &#8211; 3 tens = 4 tens<br \/>\nSo, 70 &#8211; 30 = 40.<\/p>\n<p>Question 2.<br \/>\n40 &#8211; 20 = __________<br \/>\n____________ tens &#8211; ____________ tens = ____________ tens<br \/>\nSo, 40 &#8211; 20 = ____________ .<br \/>\nAnswer:<br \/>\n4 tens &#8211; 2 tens = 2 tens.<br \/>\n40 &#8211; 20 = 20.<\/p>\n<p>Explanation:<br \/>\nPlace value\u00a0is the\u00a0value of each digit in a number.<br \/>\n4 value in 40 =4 tens<br \/>\n2 value in 20 = 2 tens<br \/>\nSubtract the two numbers:<br \/>\n4 tens &#8211; 2 tens = 2 tens.<br \/>\nSo, 40 &#8211; 20 = 20.<\/p>\n<p><strong>Apply and Grow: Practice<\/strong><\/p>\n<p>Question 3.<br \/>\n90 &#8211; 30 = ?<br \/>\n____________ tens &#8211; ____________ tens = ____________ tens<br \/>\nSo, 90 &#8211; 30 = ____________ .<br \/>\nAnswer:<br \/>\n9 tens &#8211; 3 tens = 6 tens.<br \/>\n90 &#8211; 30 = 60.<\/p>\n<p>Explanation:<br \/>\nPlace value\u00a0is the\u00a0value of each digit in a number.<br \/>\n9 value in 90 =9 tens<br \/>\n3 value in 30 = 3 tens<br \/>\nSubtract the two numbers:<br \/>\n9 tens &#8211; 3 tens = 6 tens.<br \/>\nSo, 90 &#8211; 30 = 60.<\/p>\n<p>Question 4.<br \/>\n50 &#8211; 10 = ?<br \/>\n____________ tens &#8211; ____________ tens = ____________ tens<br \/>\nSo, 50 &#8211; 10 = ____________ .<br \/>\nAnswer:<br \/>\n5 tens &#8211; 1 tens = 4 tens.<br \/>\n50 &#8211; 10 = 40.<\/p>\n<p>Explanation:<br \/>\nPlace value\u00a0is the\u00a0value of each digit in a number.<br \/>\n5 value in 50 = 5 tens<br \/>\n1 value in 10 = 1 tens<br \/>\nSubtract the two numbers:<br \/>\n5 tens &#8211; 1 tens = 4 tens.<br \/>\nSo, 50 &#8211; 10 = 40.<\/p>\n<p>Question 5.<br \/>\n30 &#8211; 20 = __________<br \/>\nAnswer:<br \/>\n30 &#8211; 20 = 10.<\/p>\n<p>Explanation:<br \/>\nPlace value\u00a0is the\u00a0value of each digit in a number.<br \/>\n3 value in 30 = 5 tens<br \/>\n2 value in 20 = 2 tens<br \/>\nSubtract the two numbers:<br \/>\n3 tens &#8211; 2 tens = 1 tens.<br \/>\nSo, 30 &#8211; 20 = 10.<\/p>\n<p>Question 6.<br \/>\n40 &#8211; 40 = __________<br \/>\nAnswer:<br \/>\n40 &#8211; 40 = 0.<\/p>\n<p>Explanation:<br \/>\nPlace value\u00a0is the\u00a0value of each digit in a number.<br \/>\n4 value in 40 = 4 tens<br \/>\n4 value in 40 = 4 tens<br \/>\nSubtract the two numbers:<br \/>\n4 tens &#8211; 4 tens = 0 tens.<br \/>\nSo, 40 &#8211; 40 = 0.<\/p>\n<p>Question 7.<br \/>\n80 &#8211; 50 = __________<br \/>\nAnswer:<br \/>\n80 &#8211; 50 = 30.<\/p>\n<p>Explanation:<br \/>\nPlace value\u00a0is the\u00a0value of each digit in a number.<br \/>\n8 value in 80 = 8 tens<br \/>\n5 value in 50 = 5 tens<br \/>\nSubtract the two numbers:<br \/>\n8 tens &#8211; 5 tens = 3 tens.<br \/>\nSo, 80 &#8211; 50 = 30.<\/p>\n<p>Question 8.<br \/>\n90 &#8211; 70 = ___________<br \/>\nAnswer:<br \/>\n90 &#8211; 70 = 20.<\/p>\n<p>Explanation:<br \/>\nPlace value\u00a0is the\u00a0value of each digit in a number.<br \/>\n9 value in 90 = 9 tens<br \/>\n7 value in 70 = 7 tens<br \/>\nSubtract the two numbers:<br \/>\n9 tens &#8211; 7 tens = 2 tens.<br \/>\nSo, 90 &#8211; 70 = 20.<\/p>\n<p>Question 9.<br \/>\n20 &#8211; __________ = 10<br \/>\nAnswer:<br \/>\n20 &#8211; 10 = 10.<\/p>\n<p>Explanation:<br \/>\nHere, the minuend is 20.<br \/>\nDifference is 10.<br \/>\nLet the subtrahend be X.<br \/>\nNow, subtract the numbers.<br \/>\n20 &#8211; X = 10.<br \/>\n20 = 10 + X<br \/>\n20 &#8211; 10 = X<br \/>\n10 = X.<br \/>\nHence, 20 &#8211; 10 = 10.<\/p>\n<p>Question 10.<br \/>\n50 &#8211; __________ = 20<br \/>\nAnswer:<br \/>\n50 &#8211; 30 = 20.<\/p>\n<p>Explanation:<br \/>\nHere, the minuend is 50.<br \/>\nDifference is 20.<br \/>\nLet the subtrahend be X.<br \/>\nNow, subtract the numbers.<br \/>\n50 &#8211; X = 20.<br \/>\n50 = 20 + X<br \/>\n50 &#8211; 20 = X<br \/>\n30 = X.<br \/>\nHence, 50 &#8211; 30 = 20.<\/p>\n<p>Question 11.<br \/>\n<strong>DIG DEEPER!<\/strong><br \/>\nWhich choices match the model?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26912\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-8-Add-and-Subtract-Tens-36.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 8 Add and Subtract Tens 36\" width=\"155\" height=\"93\" \/><br \/>\n50 &#8211; 30\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a080 &#8211; 30<br \/>\n5 tens &#8211; 3 tens\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a08 tens &#8211; 3 tens<br \/>\nAnswer:<br \/>\n8 tens &#8211; 3 tens = 5 tens.<\/p>\n<p>Explanation:<br \/>\nIn the given picture,\u00a0 total there are eight lines.<br \/>\nConsider each line value is 10. Out of them 3 lines are removed.<br \/>\n=&gt; 80 &#8211; 30 = 50.<br \/>\n2. 50 &#8211; 30 = 20<br \/>\n3. 5 tens &#8211; 3 tens = 2 tens.<br \/>\n4. 8 tens &#8211; 3 tens = 5 tens.<br \/>\nHence, 4th equation is suitable for the model .<\/p>\n<p><strong>Think and Grow: Modeling Real Life<\/strong><\/p>\n<p>You have 80 math problems. You have 40 fewer spelling words. How many spelling words do you have?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26911\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-8-Add-and-Subtract-Tens-37.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 8 Add and Subtract Tens 37\" width=\"198\" height=\"150\" \/><br \/>\nModel:<\/p>\n<p>Subtraction equation:<\/p>\n<p>______________ spelling words<\/p>\n<p>Answer:<br \/>\nNumber of spelling words I have = 40.<\/p>\n<p>Explanation:<br \/>\nTotal number of math problems I have = 80<br \/>\nNumber of fewer spelling words = 40<\/p>\n<p>Subtraction equation:<br \/>\nNumber of spelling words do you have = Total number of math problems I have &#8211; Number of fewer spelling words<br \/>\n= 80 &#8211; 40<br \/>\n= 40.<br \/>\nHence, Number of spelling words I have = 40.<\/p>\n<p><strong>Show and Grow<\/strong><\/p>\n<p>Question 12.<br \/>\nThere are 60 students in a play. A football team has 30 fewer students. How many students are on the football team?<br \/>\nModel:<\/p>\n<p>Subtraction equation:<\/p>\n<p>______________ students<\/p>\n<p>Answer:<br \/>\nNumber of students on the football team = 30.<\/p>\n<p>Explanation:<br \/>\nTotal number of students in a play = 60<br \/>\nNumber of fewer students in a football team = 30<\/p>\n<p>Subtraction equation:<br \/>\nNumber of students on the football team = Total number of students in a play &#8211; Number of fewer students in a football team<br \/>\n= 60 &#8211; 30<br \/>\n= 30<br \/>\nHence, Number of students on the football team = 30.<\/p>\n<h3><a id=\"Subtract_Tens_Practice_8.5\"><\/a>Subtract Tens Practice 8.5<\/h3>\n<p>Question 1.<br \/>\n70 &#8211; 50 = ?<br \/>\n____________ tens &#8211; ____________ tens = ____________ tens<br \/>\nSo, 70 &#8211; 50 = ____________ .<br \/>\nAnswer:<br \/>\n70 &#8211; 50 = 20.<br \/>\n7 tens &#8211; 5 tens = 2 tens.<\/p>\n<p>Explanation:<br \/>\nPlace value\u00a0is the\u00a0value of each digit in a number.<br \/>\n7 value in 70 = 7 tens<br \/>\n5 value in 50 = 5 tens<br \/>\nSubtract the two numbers:<br \/>\n7 tens &#8211; 5 tens = 2 tens.<br \/>\nSo, 70 &#8211; 50 = 20.<\/p>\n<p>Question 2.<br \/>\n60 &#8211; 20 = ?<br \/>\n____________ tens &#8211; ____________ tens = ____________ tens<br \/>\nSo, 60 &#8211; 20 = ____________ .<br \/>\nAnswer:<br \/>\n60 &#8211; 20 = 40.<br \/>\n6 tens &#8211; 2 tens = 4 tens.<\/p>\n<p>Explanation:<br \/>\nPlace value\u00a0is the\u00a0value of each digit in a number.<br \/>\n6 value in 60 = 6 tens<br \/>\n2 value in 20 = 2 tens<br \/>\nSubtract the two numbers:<br \/>\n6 tens &#8211; 2 tens = 4 tens.<br \/>\nSo, 60 &#8211; 20 = 40.<\/p>\n<p>Question 3.<br \/>\n60 &#8211; 60 = __________<br \/>\nAnswer:<br \/>\n60 &#8211; 60 = 0.<\/p>\n<p>Explanation:<br \/>\nHere, the minuend is 60 and subtrahend is 60.<br \/>\nSubtract the two numbers:<br \/>\n60 &#8211; 60 = 0.<\/p>\n<p>Question 4.<br \/>\n30 &#8211; 10 = ____________<br \/>\nAnswer:<br \/>\n30 &#8211; 10 = 20.<\/p>\n<p>Explanation:<br \/>\nHere, the minuend is 30 and subtrahend is 10.<br \/>\nSubtract the two numbers:<br \/>\n30 &#8211; 10 = 20.<\/p>\n<p>Question 5.<br \/>\n70 &#8211; __________ = 0<br \/>\nAnswer:<br \/>\n70 &#8211; 70 =0.<\/p>\n<p>Explanation:<br \/>\nHere, the minuend is 70.<br \/>\nLet the subtrahend be X<br \/>\nDifference = 0.<br \/>\nSubtract the two numbers:<br \/>\n70 &#8211; X = 0<br \/>\n70 = 0 + X<br \/>\n70 &#8211; 0 = X<br \/>\n70 = X<br \/>\nEquation is 70 &#8211; 70 =0.<\/p>\n<p>Question 6.<br \/>\n50 &#8211; ___________ = 40<br \/>\nAnswer:<br \/>\n50 &#8211; 10 =40.<\/p>\n<p>Explanation:<br \/>\nHere, the minuend is 50.<br \/>\nLet the subtrahend be X<br \/>\nDifference = 40.<br \/>\nSubtract the two numbers:<br \/>\n50 &#8211; X = 40<br \/>\n50 = 40 + X<br \/>\n50 &#8211; 40 = X<br \/>\n10 = X<br \/>\nEquation is 50 &#8211; 10 =40.<\/p>\n<p>Question 7.<br \/>\n40 &#8211; ____________ = 20<br \/>\nAnswer:<br \/>\n40 &#8211; 20 = 20.<\/p>\n<p>Explanation:<br \/>\nHere, the minuend is 40.<br \/>\nLet the subtrahend be X<br \/>\nDifference = 20.<br \/>\nSubtract the two numbers:<br \/>\n40 &#8211; X = 20<br \/>\n40 = 20 + X<br \/>\n40 &#8211; 20 = X<br \/>\n20 = X<br \/>\nEquation is 40 &#8211; 20 = 20.<\/p>\n<p>Question 8.<br \/>\n90 &#8211; ____________ = 50<br \/>\nAnswer:<br \/>\n90 &#8211; 40 =50.<\/p>\n<p>Explanation:<br \/>\nHere, the minuend is 90.<br \/>\nLet the subtrahend be X<br \/>\nDifference = 50.<br \/>\nSubtract the two numbers:<br \/>\n90 &#8211; X = 50<br \/>\n90 = 50 + X<br \/>\n90 &#8211; 50 = X<br \/>\n40 = X<br \/>\nEquation is 90 &#8211; 40 =50.<\/p>\n<p>Question 9.<br \/>\n<strong>DIG DEEPER!<\/strong><br \/>\nWhich choices match the model?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26910\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-8-Add-and-Subtract-Tens-38.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 8 Add and Subtract Tens 38\" width=\"173\" height=\"97\" \/><br \/>\n9o &#8211; 50\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 40 &#8211; 50<br \/>\n4 tens &#8211; 5 ones\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 9 tens &#8211; 5 tens<br \/>\nAnswer:<br \/>\n9 tens &#8211; 5 tens = 4 tens.<\/p>\n<p>Explanation:<br \/>\nIn the given picture,\u00a0 total there are nine lines.<br \/>\nConsider each line value is 10. Out of them 5 lines are removed.<br \/>\n=&gt; 9 tens &#8211; 5 tens = 4 tens<br \/>\n2. 90 &#8211; 50 = 40<br \/>\n3. 40 &#8211; 50 = -10<br \/>\n4. 4 tens &#8211; 5 ones = 40 + 5 = 45.<br \/>\nHence, out of four choices, the first choice is correct for the model than other three equations.<\/p>\n<p>Question 10.<br \/>\n<strong>Modeling Real Life<\/strong><br \/>\nThere are 40 chairs in the library. There are 30 fewer tables than chairs. How many tables are there?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26909\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-8-Add-and-Subtract-Tens-39.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 8 Add and Subtract Tens 39\" width=\"95\" height=\"99\" \/><\/p>\n<p>___________ tables<br \/>\nAnswer:<br \/>\nNumber of tables are there = 10.<\/p>\n<p>Explanation:<br \/>\nTotal number of chairs in a library = 40<br \/>\nNumber of fewer tables than chairs = 30<br \/>\nNumber of tables are there = Total number of chairs in a library &#8211; Number of fewer tables than chairs<br \/>\n= 40 &#8211; 30<br \/>\n= 10.<br \/>\nHence, Number of tables are there = 10.<\/p>\n<p><strong>Review &amp; Refresh<\/strong><\/p>\n<p>Question 11.<br \/>\n11 &#8211; 7 = ____________<br \/>\nAnswer:<br \/>\n11 &#8211; 7 = 4<\/p>\n<p>Explanation:<br \/>\nHere, the minuend is 17 and subtrahend is 7.<br \/>\nSubtract the two numbers:<br \/>\n11 &#8211; 7 = 4<br \/>\nHence, 11 &#8211; 7 = 4.<\/p>\n<p>Question 12.<br \/>\n16 &#8211; 8 = ____________<br \/>\nAnswer:<br \/>\n16 &#8211; 8 = 8.<\/p>\n<p>Explanation:<br \/>\nHere, the minuend is 16 and subtrahend is 8.<br \/>\nSubtract the two numbers:<br \/>\n16 &#8211; 8 = 8.<br \/>\nHence, 16 &#8211; 8 = 8.<\/p>\n<p>Question 13.<br \/>\n15 &#8211; 8 = ____________<br \/>\nAnswer:<br \/>\n15 &#8211; 8 = 7.<\/p>\n<p>Explanation:<br \/>\nHere, the minuend is 15 and subtrahend is 8.<br \/>\nSubtract the two numbers:<br \/>\n15 &#8211; 8 = 7.<br \/>\nHence, 15 &#8211; 8 = 7.<\/p>\n<p>Question 14.<br \/>\n18 &#8211; 9 = ____________<br \/>\nAnswer:<br \/>\n18 &#8211; 9 = 9.<\/p>\n<p>Explanation:<br \/>\nHere, the minuend is 18 and subtrahend is 9.<br \/>\nSubtract the two numbers:<br \/>\n18 &#8211; 9 = 9.<br \/>\nHence, 18 &#8211; 9 = 9.<\/p>\n<h3><a id=\"Lesson_8.6_Subtract_Tens_Using_a_Number_Line\"><\/a>Lesson 8.6 Subtract Tens Using a Number Line<\/h3>\n<p><strong>Explore and Grow<\/strong><\/p>\n<p>Write the missing numbers. How do the hops help you solve?<\/p>\n<p>40 &#8211; 20 = ___________<\/p>\n<p><img loading=\"lazy\" class=\"alignnone size-full wp-image-26929\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-40.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 8 Add and Subtract Tens 40\" width=\"440\" height=\"158\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-40.png 440w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-40-300x108.png 300w\" sizes=\"(max-width: 440px) 100vw, 440px\" \/><br \/>\nAnswer:<br \/>\n40 &#8211; 20 = 20.<\/p>\n<p>Explanation:<br \/>\nIn math, a number line can be defined as a straight line with numbers placed at equal intervals or segments along its length.<br \/>\nHere, we need to represent 20 subtracted from 40.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33558\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.6-Subtract-Tens-Using-a-Number-Line1.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Lesson-8.6-Subtract-Tens-Using-a-Number- Line1\" width=\"493\" height=\"172\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.6-Subtract-Tens-Using-a-Number-Line1.png 493w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.6-Subtract-Tens-Using-a-Number-Line1-300x105.png 300w\" sizes=\"(max-width: 493px) 100vw, 493px\" \/><\/p>\n<p><strong>Show and Grow<\/strong><\/p>\n<p>Question 1.<br \/>\n80 &#8211; 50 = __________<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26928\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-41.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 8 Add and Subtract Tens 41\" width=\"424\" height=\"37\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-41.png 424w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-41-300x26.png 300w\" sizes=\"(max-width: 424px) 100vw, 424px\" \/><br \/>\nAnswer:<br \/>\n80 &#8211; 50 = 30.<\/p>\n<p>Explanation:<br \/>\nHere, we need to represent 50 subtracted from 80.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33562\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.6-Subtract-Tens-Using-a-Number-Line2.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Lesson-8.6-Subtract-Tens-Using-a-Number- Line2\" width=\"896\" height=\"159\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.6-Subtract-Tens-Using-a-Number-Line2.png 896w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.6-Subtract-Tens-Using-a-Number-Line2-300x53.png 300w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.6-Subtract-Tens-Using-a-Number-Line2-768x136.png 768w\" sizes=\"(max-width: 896px) 100vw, 896px\" \/><\/p>\n<p>Question 2.<br \/>\n70 &#8211; 30 = ___________<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26927\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-42.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 8 Add and Subtract Tens 42\" width=\"429\" height=\"36\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-42.png 429w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-42-300x25.png 300w\" sizes=\"(max-width: 429px) 100vw, 429px\" \/><br \/>\nAnswer:<br \/>\n70 &#8211; 30 = 40.<\/p>\n<p>Explanation:<br \/>\nHere, we need to represent 30 subtracted from 70.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33566\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.6-Subtract-Tens-Using-a-Number-Line-Show-and-Grow2-1.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Lesson-8.6-Subtract-Tens-Using-a-Number- Line-Show and Grow2\" width=\"736\" height=\"145\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.6-Subtract-Tens-Using-a-Number-Line-Show-and-Grow2-1.png 736w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.6-Subtract-Tens-Using-a-Number-Line-Show-and-Grow2-1-300x59.png 300w\" sizes=\"(max-width: 736px) 100vw, 736px\" \/><\/p>\n<p><strong>Apply and Grow: Practice<\/strong><\/p>\n<p>Question 3.<br \/>\n60 &#8211; 20 = __________<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26926\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-43.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 8 Add and Subtract Tens 43\" width=\"426\" height=\"38\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-43.png 426w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-43-300x27.png 300w\" sizes=\"(max-width: 426px) 100vw, 426px\" \/><br \/>\nAnswer:<br \/>\n60 &#8211; 20 = 40.<\/p>\n<p>Explanation:<br \/>\nHere, we need to represent 20 subtracted from 60.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33569\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.6-Subtract-Tens-Using-a-Number-Line-Apply-and-Grow-Practice3.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Lesson-8.6-Subtract-Tens-Using-a-Number- Line-Apply-and- Grow-Practice3\" width=\"516\" height=\"132\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.6-Subtract-Tens-Using-a-Number-Line-Apply-and-Grow-Practice3.png 516w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.6-Subtract-Tens-Using-a-Number-Line-Apply-and-Grow-Practice3-300x77.png 300w\" sizes=\"(max-width: 516px) 100vw, 516px\" \/><\/p>\n<p>Question 4.<br \/>\n40 &#8211; 30 = ____________<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26925\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-44.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 8 Add and Subtract Tens 44\" width=\"424\" height=\"26\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-44.png 424w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-44-300x18.png 300w\" sizes=\"(max-width: 424px) 100vw, 424px\" \/><br \/>\nAnswer:<br \/>\n40 &#8211; 30 = 10.<\/p>\n<p>Explanation:<br \/>\nHere, we need to represent 30 subtracted from 40.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33570\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.6-Subtract-Tens-Using-a-Number-Line-Apply-and-Grow-Practice4.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Lesson-8.6-Subtract-Tens-Using-a-Number- Line-Apply-and-Grow-Practice4\" width=\"669\" height=\"130\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.6-Subtract-Tens-Using-a-Number-Line-Apply-and-Grow-Practice4.png 669w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.6-Subtract-Tens-Using-a-Number-Line-Apply-and-Grow-Practice4-300x58.png 300w\" sizes=\"(max-width: 669px) 100vw, 669px\" \/><\/p>\n<p>Question 5.<br \/>\n90 &#8211; 40 = ____________<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26925\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-44.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 8 Add and Subtract Tens 44\" width=\"424\" height=\"26\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-44.png 424w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-44-300x18.png 300w\" sizes=\"(max-width: 424px) 100vw, 424px\" \/><br \/>\nAnswer:<br \/>\n90 &#8211; 40 = 50.<\/p>\n<p>Explanation:<br \/>\nHere, we need to represent 40 subtracted from 90.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33573\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.6-Subtract-Tens-Using-a-Number-Line-Apply-and-Grow-Practice5.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Lesson-8.6-Subtract-Tens-Using-a-Number- Line-Apply-and-Grow-Practice5\" width=\"800\" height=\"132\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.6-Subtract-Tens-Using-a-Number-Line-Apply-and-Grow-Practice5.png 800w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.6-Subtract-Tens-Using-a-Number-Line-Apply-and-Grow-Practice5-300x50.png 300w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.6-Subtract-Tens-Using-a-Number-Line-Apply-and-Grow-Practice5-768x127.png 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/><\/p>\n<p>Question 6.<br \/>\n90 &#8211; 70 = ____________<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26925\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-44.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 8 Add and Subtract Tens 44\" width=\"424\" height=\"26\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-44.png 424w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-44-300x18.png 300w\" sizes=\"(max-width: 424px) 100vw, 424px\" \/><br \/>\nAnswer:<br \/>\n90 &#8211; 70 = 20.<\/p>\n<p>Explanation:<br \/>\nHere, we need to represent 70 subtracted from 90.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33574\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.6-Subtract-Tens-Using-a-Number-Line-Apply-and-Grow-Practice6.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Lesson-8.6-Subtract-Tens-Using-a-Number- Line-Apply-and-Grow-Practice6\" width=\"898\" height=\"127\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.6-Subtract-Tens-Using-a-Number-Line-Apply-and-Grow-Practice6.png 898w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.6-Subtract-Tens-Using-a-Number-Line-Apply-and-Grow-Practice6-300x42.png 300w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.6-Subtract-Tens-Using-a-Number-Line-Apply-and-Grow-Practice6-768x109.png 768w\" sizes=\"(max-width: 898px) 100vw, 898px\" \/><\/p>\n<p>Question 7.<br \/>\n<strong>MP Structure<\/strong><br \/>\nWrite the equation that matches the number line.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26924\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-45.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 8 Add and Subtract Tens 45\" width=\"426\" height=\"145\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-45.png 426w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-45-300x102.png 300w\" sizes=\"(max-width: 426px) 100vw, 426px\" \/><br \/>\nAnswer:<br \/>\n80 &#8211; 40 = 40<\/p>\n<p>Explanation:<br \/>\n80 &#8211; 10 -10 &#8211; 10 -10<br \/>\n= 70 -10 &#8211; 10 -10<br \/>\n= 60 &#8211; 10 -10<br \/>\n= 50 -10<br \/>\n= 40.<\/p>\n<p><strong>Think and Grow: Modeling Real Life<\/strong><\/p>\n<p>You have a bucket of 80 golf balls. You hit 60 of them. Your friend has 28 golf balls left. Who has more golf balls left?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26923\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-46.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 8 Add and Subtract Tens 46\" width=\"90\" height=\"99\" \/><br \/>\nModel:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26922\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-47.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 8 Add and Subtract Tens 47\" width=\"425\" height=\"32\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-47.png 425w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-47-300x23.png 300w\" sizes=\"(max-width: 425px) 100vw, 425px\" \/><br \/>\nSubtraction equation:<br \/>\nCompare: __________ \u25cb ___________<br \/>\nWho has more golf balls left?\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0You\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0Friend<br \/>\nAnswer:<br \/>\nMy friend has left 8 golf balls more than me.<\/p>\n<p>Given:<br \/>\nTotal number of golf balls I have = 80<br \/>\nNumber of golf balls I hit out of them = 60<br \/>\nExplanation:<br \/>\nNumber of gold balls I left = Total number of golf balls I have &#8211; Number of golf balls I hit out of them<br \/>\n= 80 &#8211; 60<br \/>\n= 20<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-34074\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Think-and-Grow-Modeling-Real-Life.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Think and Grow-Modeling-Real-Life\" width=\"818\" height=\"147\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Think-and-Grow-Modeling-Real-Life.png 818w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Think-and-Grow-Modeling-Real-Life-300x54.png 300w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Think-and-Grow-Modeling-Real-Life-768x138.png 768w\" sizes=\"(max-width: 818px) 100vw, 818px\" \/><br \/>\nNumber of golf balls my friend left = 28<br \/>\nComparison:<br \/>\nNumber of golf balls who left more = Number of golf balls my friend left &#8211;\u00a0 Number of gold balls I left<br \/>\n= 28 &#8211; 20<br \/>\n= 8.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33575\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.6-Subtract-Tens-Using-a-Number-Line-Think-and-Grow-Modeling-Real-Life.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Lesson-8.6-Subtract-Tens-Using-a-Number- Line-Think and Grow-Modeling-Real-Life\" width=\"190\" height=\"92\" \/><br \/>\nHence, my friend has left 8 golf balls more than me.<\/p>\n<p><strong>Show and Grow<\/strong><\/p>\n<p>Question 8.<br \/>\nPack A has 50 batteries. 40 of them have been used. Pack B has 15 batteries. Which pack has more bafferies left?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26921\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-48.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 8 Add and Subtract Tens 48\" width=\"43\" height=\"109\" \/><br \/>\nModel:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26920\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-49.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 8 Add and Subtract Tens 49\" width=\"422\" height=\"29\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-49.png 422w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-49-300x21.png 300w\" sizes=\"(max-width: 422px) 100vw, 422px\" \/><br \/>\nSubtraction equation:<br \/>\nCompare: __________ \u25cb ___________<br \/>\nWho has more golf balls left?\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0Pack A\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 Pack B<br \/>\nAnswer:<br \/>\n5 batteries are left more in pack B than pack A.<\/p>\n<p>Given:<br \/>\nTotal number of batteries in pack A has= 50<br \/>\nNumber of batteries used in pack A = 40<br \/>\nTotal number of batteries in pack B has = 15<br \/>\nExplanation:<br \/>\nNumber of batteries left in pack A = Total number of batteries in pack A has &#8211; Number of batteries used in pack A<br \/>\n= 50 &#8211; 40<br \/>\n= 10.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-34076\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-8.6-Show-and-Grow-8..png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-8.6-Show-and-Grow-8.\" width=\"633\" height=\"134\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-8.6-Show-and-Grow-8..png 633w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-8.6-Show-and-Grow-8.-300x64.png 300w\" sizes=\"(max-width: 633px) 100vw, 633px\" \/><br \/>\nComparison:<br \/>\nNumber of batteries which pack has left more = Total number of batteries in pack B has &#8211; Number of batteries left in pack A<br \/>\n= 15 &#8211; 10<br \/>\n= 5<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33968\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-8.6-Show-and-Grow8.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-8.6-Show-and-Grow8\" width=\"259\" height=\"99\" \/><br \/>\nHence,5 batteries are left more in pack B than pack A.<\/p>\n<h3><a id=\"Subtract_Tens_Using_a_Number_Line_Practice_8.6\"><\/a>Subtract Tens Using a Number Line Practice 8.6<\/h3>\n<p>Question 1.<br \/>\n50 &#8211; 30 = _____________<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26919\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-50.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 8 Add and Subtract Tens 50\" width=\"424\" height=\"41\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-50.png 424w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-50-300x29.png 300w\" sizes=\"(max-width: 424px) 100vw, 424px\" \/><br \/>\nAnswer:<br \/>\n50 &#8211; 30 = 20.<\/p>\n<p>Explanation:<br \/>\nHere, we need to represent 30 subtracted from 50.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33578\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Subtract-Tens-Using-a-Number-Line-Practice-8.6.1.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Subtract-Tens-Using-a-Number-Line-Practice-8.6.1\" width=\"531\" height=\"160\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Subtract-Tens-Using-a-Number-Line-Practice-8.6.1.png 531w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Subtract-Tens-Using-a-Number-Line-Practice-8.6.1-300x90.png 300w\" sizes=\"(max-width: 531px) 100vw, 531px\" \/><\/p>\n<p>Question 2.<br \/>\n80 &#8211; 60 = ____________<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26918\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-51.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 8 Add and Subtract Tens 51\" width=\"423\" height=\"32\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-51.png 423w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-51-300x23.png 300w\" sizes=\"(max-width: 423px) 100vw, 423px\" \/><br \/>\nAnswer:<br \/>\n80 &#8211; 60 = 20.<\/p>\n<p>Explanation:<br \/>\nHere, we need to represent 60 subtracted from 80.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33580\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Subtract-Tens-Using-a-Number-Line-Practice-8.6.2.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Subtract-Tens-Using-a-Number-Line-Practice-8.6.2\" width=\"922\" height=\"137\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Subtract-Tens-Using-a-Number-Line-Practice-8.6.2.png 922w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Subtract-Tens-Using-a-Number-Line-Practice-8.6.2-300x45.png 300w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Subtract-Tens-Using-a-Number-Line-Practice-8.6.2-768x114.png 768w\" sizes=\"(max-width: 922px) 100vw, 922px\" \/><\/p>\n<p>Question 3.<br \/>\n90 &#8211; 20 = ____________<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26918\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-51.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 8 Add and Subtract Tens 51\" width=\"423\" height=\"32\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-51.png 423w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-51-300x23.png 300w\" sizes=\"(max-width: 423px) 100vw, 423px\" \/><br \/>\nAnswer:<br \/>\n90 &#8211; 20 = 70.<\/p>\n<p>Explanation:<br \/>\nHere, we need to represent 20 subtracted from 90.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33582\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Subtract-Tens-Using-a-Number-Line-Practice-8.6.3.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Subtract-Tens-Using-a-Number-Line-Practice-8.6.3\" width=\"614\" height=\"131\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Subtract-Tens-Using-a-Number-Line-Practice-8.6.3.png 614w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Subtract-Tens-Using-a-Number-Line-Practice-8.6.3-300x64.png 300w\" sizes=\"(max-width: 614px) 100vw, 614px\" \/><\/p>\n<p>Question 4.<br \/>\n<strong>MP Structure<\/strong><br \/>\nWrite the equation that matches the number line.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26917\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-52.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 8 Add and Subtract Tens 52\" width=\"423\" height=\"137\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-52.png 423w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-52-300x97.png 300w\" sizes=\"(max-width: 423px) 100vw, 423px\" \/><br \/>\nAnswer:<br \/>\n60 &#8211; 50 = 10.<\/p>\n<p>Explanation:<br \/>\nHere we need to subtract 10 5times from 60.<br \/>\n60 &#8211; 10 -10 -10 -10 -10<br \/>\n= 50 -10 -10 -10 -10<br \/>\n=\u00a0 40 &#8211; 10 -10 -10<br \/>\n= 30 &#8211; 10 -10<br \/>\n= 20 &#8211; 10<br \/>\n= 10.<\/p>\n<p>Question 5.<br \/>\n<strong>Modeling Real Life<\/strong><br \/>\nYou have 80 raffle tickets and give away 30 of them. Your friend has 47 raffle tickets. Who has more raffle tickets?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-26916\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-53.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 8 Add and Subtract Tens 53\" width=\"87\" height=\"66\" \/><\/p>\n<p><img loading=\"lazy\" class=\"alignnone size-full wp-image-26915\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-54.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 8 Add and Subtract Tens 54\" width=\"429\" height=\"26\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-54.png 429w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-8-Add-and-Subtract-Tens-54-300x18.png 300w\" sizes=\"(max-width: 429px) 100vw, 429px\" \/><\/p>\n<p>Who has more raffle tickets? You Friend<\/p>\n<p>Answer:<br \/>\nI have 5 raffle tickets more than my friend.<\/p>\n<p>Given:<br \/>\nTotal number of raffle tickets = 80<br \/>\nNumber of raffle tickets I gave away = 30<br \/>\nExplanation:<br \/>\nNumber of raffle tickets I have now = Total number of raffle tickets &#8211; Number of raffle tickets I gave away<br \/>\n= 80 -30<br \/>\n= 50<br \/>\nNumber of raffles tickets my friend has = 47<\/p>\n<p>Comparison:<br \/>\nNumber of raffle ticket who has more = Number of raffle tickets I have now &#8211; Number of raffles tickets my friend has<br \/>\n= 50 &#8211; 47<br \/>\n= 3<br \/>\nHence, I have 5 raffle tickets more than my friend.<\/p>\n<p><strong>Review &amp; Refresh<\/strong><\/p>\n<p>Question 6.<br \/>\n13 &#8211; 8 = ?<br \/>\nThink 8 + __________ = 13.<br \/>\nSo, 13 &#8211; 8 = __________ .<br \/>\nAnswer:<br \/>\n13 &#8211; 8 = 5.<\/p>\n<p>Explanation:<br \/>\nThink 8 + ____5______ = 13.<br \/>\nSo, 13 &#8211; 8 = ___5_______ .<\/p>\n<p>Question 7.<br \/>\n15 &#8211; 7 = ?<br \/>\nThink 7 + _________ = 15<br \/>\nSo, 15 &#8211; 7 = ____________ .<br \/>\nAnswer:<br \/>\n15 &#8211; 7 = 8.<\/p>\n<p>Explanation:<br \/>\nThink 7 + ____8_____ = 15<br \/>\nSo, 15 &#8211; 7 = ______8______ .<\/p>\n<h3><a id=\"Lesson_8.7_Use_Addition_to_Subtract_Tens\"><\/a>Lesson 8.7 Use Addition to Subtract Tens<\/h3>\n<p><strong>Explore and Grow<\/strong><\/p>\n<p>Complete each equation. What do you notice?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-27436\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-55.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 8 Add and Subtract Tens 55\" width=\"432\" height=\"408\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-55.png 432w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-55-300x283.png 300w\" sizes=\"(max-width: 432px) 100vw, 432px\" \/><br \/>\nAnswer:<br \/>\n20 + 50 = 70<br \/>\n50 &#8211; 20 = 30.<\/p>\n<p>Explanation:<br \/>\nHere, for number 20 we are adding 5 times 10.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33584\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.7-Use-Addition-to-Subtract-Tens.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Lesson 8.7-Use-Addition-to-Subtract-Tens\" width=\"945\" height=\"162\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.7-Use-Addition-to-Subtract-Tens.png 945w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.7-Use-Addition-to-Subtract-Tens-300x51.png 300w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.7-Use-Addition-to-Subtract-Tens-768x132.png 768w\" sizes=\"(max-width: 945px) 100vw, 945px\" \/><\/p>\n<p>Here, we are subtracting 20 from number 50.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33587\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.7-Use-Addition-to-Subtract-Tens.-1.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Lesson 8.7-Use-Addition-to-Subtract-Tens.\" width=\"469\" height=\"146\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.7-Use-Addition-to-Subtract-Tens.-1.png 469w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.7-Use-Addition-to-Subtract-Tens.-1-300x93.png 300w\" sizes=\"(max-width: 469px) 100vw, 469px\" \/><\/p>\n<p><strong>Show and Grow<\/strong><\/p>\n<p>Question 1.<br \/>\n90 &#8211; 70 = ?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-27435\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-56.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 8 Add and Subtract Tens 56\" width=\"422\" height=\"38\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-56.png 422w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-56-300x27.png 300w\" sizes=\"(max-width: 422px) 100vw, 422px\" \/><br \/>\nThink 70 + _________ = 90<br \/>\nSo, 90 &#8211; 70 = _________ .<br \/>\nAnswer:<br \/>\n90 &#8211; 70 = 20.<\/p>\n<p>Explanation:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33589\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.7-Use-Addition-to-Subtract-Tens-Show-and-Grow1.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Lesson 8.7-Use-Addition-to-Subtract-Tens-Show and Grow1\" width=\"544\" height=\"169\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.7-Use-Addition-to-Subtract-Tens-Show-and-Grow1.png 544w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.7-Use-Addition-to-Subtract-Tens-Show-and-Grow1-300x93.png 300w\" sizes=\"(max-width: 544px) 100vw, 544px\" \/><br \/>\nThink 70 + ____20_____ = 90<br \/>\nSo, 90 &#8211; 70 = ___20______ .<\/p>\n<p>Question 2.<br \/>\n60 &#8211; 30 = ?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-27434\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-57.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 8 Add and Subtract Tens 57\" width=\"425\" height=\"40\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-57.png 425w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-57-300x28.png 300w\" sizes=\"(max-width: 425px) 100vw, 425px\" \/><br \/>\nThink 30 + _________ = 60<br \/>\nSo, 60 &#8211; 30 = _________ .<br \/>\nAnswer:<br \/>\n60 &#8211; 30 = 30.<\/p>\n<p>Explanation:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33593\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.7-Use-Addition-to-Subtract-Tens-Show-and-Grow2.png\" alt=\"\" width=\"660\" height=\"143\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.7-Use-Addition-to-Subtract-Tens-Show-and-Grow2.png 660w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.7-Use-Addition-to-Subtract-Tens-Show-and-Grow2-300x65.png 300w\" sizes=\"(max-width: 660px) 100vw, 660px\" \/><br \/>\nThink 30 + __30___ = 60<br \/>\nSo, 60 &#8211; 30 =____30___.<\/p>\n<p><strong>Apply and Grow: Practice<\/strong><\/p>\n<p>Question 3.<br \/>\n50 &#8211; 30 = ?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-27433\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-58.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 8 Add and Subtract Tens 58\" width=\"422\" height=\"41\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-58.png 422w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-58-300x29.png 300w\" sizes=\"(max-width: 422px) 100vw, 422px\" \/><br \/>\nThink 30 + _________ = 50<br \/>\nSo, 50 &#8211; 30 = _________ .<br \/>\nAnswer:<br \/>\n50 &#8211; 30 = 20.<\/p>\n<p>Explanation:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33597\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.7-Use-Addition-to-Subtract-Tens-Apply-and-Grow-Practice3.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Lesson 8.7-Use-Addition-to-Subtract-Tens-Apply-and-Grow-Practice3\" width=\"571\" height=\"133\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.7-Use-Addition-to-Subtract-Tens-Apply-and-Grow-Practice3.png 571w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.7-Use-Addition-to-Subtract-Tens-Apply-and-Grow-Practice3-300x70.png 300w\" sizes=\"(max-width: 571px) 100vw, 571px\" \/><br \/>\nThink 30 + __20_______ = 50<br \/>\nSo, 50 &#8211; 30 = ___20______ .<\/p>\n<p>Question 4.<br \/>\n70 &#8211; 20 = ?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-27432\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-59.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 8 Add and Subtract Tens 59\" width=\"430\" height=\"25\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-59.png 430w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-59-300x17.png 300w\" sizes=\"(max-width: 430px) 100vw, 430px\" \/><br \/>\nThink 20 + _________ = 70<br \/>\nSo, 70 &#8211; 20 = _________ .<br \/>\nAnswer:<br \/>\n70 &#8211; 20 = 50.<\/p>\n<p>Explanation:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33598\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.7-Use-Addition-to-Subtract-Tens-Apply-and-Grow-Practice4.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Lesson 8.7-Use-Addition-to-Subtract-Tens-Apply-and-Grow-Practice4\" width=\"806\" height=\"151\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.7-Use-Addition-to-Subtract-Tens-Apply-and-Grow-Practice4.png 806w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.7-Use-Addition-to-Subtract-Tens-Apply-and-Grow-Practice4-300x56.png 300w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.7-Use-Addition-to-Subtract-Tens-Apply-and-Grow-Practice4-768x144.png 768w\" sizes=\"(max-width: 806px) 100vw, 806px\" \/><\/p>\n<p>Think 20 + ____50_____ = 70<br \/>\nSo, 70 &#8211; 20 = __50_______ .<\/p>\n<p>Question 5.<br \/>\n90 &#8211; 50 = ?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-27432\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-59.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 8 Add and Subtract Tens 59\" width=\"430\" height=\"25\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-59.png 430w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-59-300x17.png 300w\" sizes=\"(max-width: 430px) 100vw, 430px\" \/><br \/>\nThink 50 + _________ = 90<br \/>\nSo, 90 &#8211; 50 = _________ .<br \/>\nAnswer:<br \/>\n90 &#8211; 50 = 40.<\/p>\n<p>Explanation:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33600\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.7-Use-Addition-to-Subtract-Tens-Apply-and-Grow-Practice5.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Lesson 8.7-Use-Addition-to-Subtract-Tens-Apply-and-Grow-Practice5\" width=\"706\" height=\"151\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.7-Use-Addition-to-Subtract-Tens-Apply-and-Grow-Practice5.png 706w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.7-Use-Addition-to-Subtract-Tens-Apply-and-Grow-Practice5-300x64.png 300w\" sizes=\"(max-width: 706px) 100vw, 706px\" \/><br \/>\nThink 50 + _____40____ = 90<br \/>\nSo, 90 &#8211; 50 = _____40____ .<\/p>\n<p>Question 6.<br \/>\n<strong>MP Structure<\/strong><br \/>\nMatch the related addition and subtraction equations.<br \/>\n60 + 10 = 70\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 70 &#8211; 50 = 20<br \/>\n50 + 10 = 60\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 70 &#8211; 60 = 10<br \/>\n50 + 20 = 70\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 60 &#8211; 50 = 10<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33601\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.7-Use-Addition-to-Subtract-Tens-MP-Structure6.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Lesson 8.7-Use-Addition-to-Subtract-Tens-MP Structure6\" width=\"461\" height=\"174\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.7-Use-Addition-to-Subtract-Tens-MP-Structure6.png 461w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.7-Use-Addition-to-Subtract-Tens-MP-Structure6-300x113.png 300w\" sizes=\"(max-width: 461px) 100vw, 461px\" \/><br \/>\nExplanation:<br \/>\n60 + 10 = 70 and 70 &#8211; 60 = 10 are related addition and subtraction equations because both deals with 60, 10 and 70.<br \/>\n50 + 10 = 60 and 60 &#8211; 50 = 10 are related addition and subtraction equations because both deals with 60, 10 and 50.<br \/>\n50 + 20 = 70 and 70 &#8211; 50 = 20 are related addition and subtraction equations because both deals with 70, 20 and 50.<\/p>\n<p><strong>Think and Grow: Modeling Real Life<\/strong><\/p>\n<p>A dentist has 40 toothbrushes. She gives away 20 of them. How many toothbrushes does she have left?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-27431\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-60.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 8 Add and Subtract Tens 60\" width=\"115\" height=\"154\" \/><br \/>\nModel:<\/p>\n<p><img loading=\"lazy\" class=\"alignnone size-full wp-image-27430\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-61.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 8 Add and Subtract Tens 61\" width=\"425\" height=\"24\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-61.png 425w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-61-300x17.png 300w\" sizes=\"(max-width: 425px) 100vw, 425px\" \/><br \/>\nSubtraction equation:<\/p>\n<p>______________ toothbrushes<br \/>\nAnswer:<br \/>\nNumber of tooth brushes left = 20.<\/p>\n<p>Explanation:<br \/>\nTotal number of tooth brushes a dentist has = 40<br \/>\nNumber of tooth brushes gave away = 20<br \/>\nNumber of tooth brushes left = Total number of tooth brushes a dentist has &#8211; Number of tooth brushes gave away<br \/>\n= 40 &#8211; 20<br \/>\n= 20<br \/>\nHence, Number of tooth brushes left = 20.<\/p>\n<p><strong>Show and Grow<\/strong><\/p>\n<p>Question 7.<br \/>\nAn art room has 70 bottles of glitter. 30 have been used. How many bottles are left?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-27429\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-62.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 8 Add and Subtract Tens 62\" width=\"160\" height=\"58\" \/><br \/>\nModel:<\/p>\n<p><img loading=\"lazy\" class=\"alignnone size-full wp-image-27430\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-61.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 8 Add and Subtract Tens 61\" width=\"425\" height=\"24\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-61.png 425w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-61-300x17.png 300w\" sizes=\"(max-width: 425px) 100vw, 425px\" \/><br \/>\nSubtraction equation:<\/p>\n<p>______________ bottles<br \/>\nAnswer:<br \/>\nNumber of bottles of glitter left = 40.<\/p>\n<p>Explanation:<br \/>\nTotal number bottles of glitter in an art room = 70<br \/>\nNumber of\u00a0 bottles of glitter used = 30<br \/>\nNumber of bottles of glitter left = Total number bottles of glitter in an art room &#8211; Number of\u00a0 bottles of glitter used<br \/>\n= 70 &#8211; 30<br \/>\n= 40.<br \/>\nHence, Number of bottles of glitter left = 40.<\/p>\n<h3><a id=\"Use_Addition_to_Subtract_Tens_Practice_8.7\"><\/a>Use Addition to Subtract Tens Practice 8.7<\/h3>\n<p>Question 1.<br \/>\n70 &#8211; 40 = ?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-27428\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-63.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 8 Add and Subtract Tens 63\" width=\"425\" height=\"44\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-63.png 425w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-63-300x31.png 300w\" sizes=\"(max-width: 425px) 100vw, 425px\" \/><br \/>\nThink 40 + __________ = 70<br \/>\nSo, 70 &#8211; 40 = _________ .<br \/>\nAnswer:<br \/>\n70 &#8211; 40 = 30.<\/p>\n<p>Explanation:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33970\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Use-Addition-to-Subtract-Tens-Practice-8.7.1.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Use-Addition-to-Subtract-Tens-Practice 8.7.1\" width=\"665\" height=\"138\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Use-Addition-to-Subtract-Tens-Practice-8.7.1.png 665w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Use-Addition-to-Subtract-Tens-Practice-8.7.1-300x62.png 300w\" sizes=\"(max-width: 665px) 100vw, 665px\" \/><br \/>\nThink 40 + ____30______ = 70<br \/>\nSo, 70 &#8211; 40 = ___30______ .<\/p>\n<p>Question 2.<br \/>\n90 &#8211; 30 = ?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-27427\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-64.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 8 Add and Subtract Tens 64\" width=\"425\" height=\"24\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-64.png 425w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-64-300x17.png 300w\" sizes=\"(max-width: 425px) 100vw, 425px\" \/><br \/>\nThink 60 + __________ = 90<br \/>\nSo, 90 &#8211; 30 = _________ .<br \/>\nAnswer:<br \/>\n90 &#8211; 30 = 60.<\/p>\n<p>Explanation:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33972\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Use-Addition-to-Subtract-Tens-Practice-8.7.2.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Use-Addition-to-Subtract-Tens-Practice 8.7.2\" width=\"534\" height=\"114\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Use-Addition-to-Subtract-Tens-Practice-8.7.2.png 534w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Use-Addition-to-Subtract-Tens-Practice-8.7.2-300x64.png 300w\" sizes=\"(max-width: 534px) 100vw, 534px\" \/><\/p>\n<p>Think 60 + _____30_____ = 90<br \/>\nSo, 90 &#8211; 30 = ____60_____ .<\/p>\n<p>Question 3.<br \/>\n<strong>MP Structure<\/strong><br \/>\nMatch the related addition and subtraction equations.<br \/>\n30 + 10 = 40\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 50 &#8211; 40 = 10<br \/>\n40 + 10 = 50\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 50 &#8211; 30 = 20<br \/>\n30 + 20 = 50\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 40 &#8211; 30 = 10<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33974\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Use-Addition-to-Subtract-Tens-Practice-MP-Structure-3.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Use-Addition-to-Subtract-Tens-Practice-MP Structure-3\" width=\"449\" height=\"157\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Use-Addition-to-Subtract-Tens-Practice-MP-Structure-3.png 449w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Use-Addition-to-Subtract-Tens-Practice-MP-Structure-3-300x105.png 300w\" sizes=\"(max-width: 449px) 100vw, 449px\" \/><\/p>\n<p>Explanation:<br \/>\n30 + 10 = 40 and 40 &#8211; 30 = 10 are related addition and subtraction equations because both deals with 40, 10 and 30.<br \/>\n40 + 10 = 50 and 50 &#8211; 40 = 10 are related addition and subtraction equations because both deals with 40, 10 and 50.<br \/>\n30 + 20 = 50 and 50 &#8211; 30 = 20 are related addition and subtraction equations because both deals with 30, 20 and 50.<\/p>\n<p>Question 4.<br \/>\n<strong>Modeling Real Life<\/strong><br \/>\nNewton has 80 newspapers to deliver. He delivers 50 of them. How many newspapers does he have left?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-27426\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-65.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 8 Add and Subtract Tens 65\" width=\"169\" height=\"92\" \/><\/p>\n<p><img loading=\"lazy\" class=\"alignnone size-full wp-image-27425\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-66.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 8 Add and Subtract Tens 66\" width=\"427\" height=\"31\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-66.png 427w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-66-300x22.png 300w\" sizes=\"(max-width: 427px) 100vw, 427px\" \/><\/p>\n<p>______________ newspapers<br \/>\nAnswer:<br \/>\nNumber of newspapers left = 30.<\/p>\n<p>Explanation:<br \/>\nTotal number of newspapers to deliver = 80<br \/>\nNumber of newspapers delivered = 50<br \/>\nNumber of newspapers left = Total number of newspapers to deliver &#8211; Number of newspapers delivered<br \/>\n= 80 &#8211; 50<br \/>\n= 30.<br \/>\nHence, Number of newspapers left = 30.<\/p>\n<p><strong>Review &amp; Refresh<\/strong><\/p>\n<p>Question 5.<br \/>\nMake quick sketches to compare the numbers.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-27424\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-67.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 8 Add and Subtract Tens 67\" width=\"250\" height=\"57\" \/><br \/>\nAnswer:<br \/>\n43 &gt; 34.<br \/>\n34 &lt; 43.<\/p>\n<p>Explanation:<br \/>\n43 is greater than 34.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33977\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Use-Addition-to-Subtract-Tens-Practice-5-.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Use-Addition-to-Subtract-Tens-Practice-5-\" width=\"241\" height=\"90\" \/><br \/>\n34 is lesser than 43.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33978\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Use-Addition-to-Subtract-Tens-Practice-5-1-1.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Use-Addition-to-Subtract-Tens-Practice-5-\" width=\"232\" height=\"102\" \/><\/p>\n<h3><a id=\"Lesson_8.8_Add_Tens_to_a_Number\"><\/a>Lesson 8.8 Add Tens to a Number<\/h3>\n<p><strong>Explore and Grow<\/strong><\/p>\n<p><img loading=\"lazy\" class=\"alignnone size-full wp-image-27445\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-68.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 8 Add and Subtract Tens 68\" width=\"421\" height=\"261\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-68.png 421w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-68-300x186.png 300w\" sizes=\"(max-width: 421px) 100vw, 421px\" \/><\/p>\n<p>15 + 10 = ________\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a027 + 10 = __________<br \/>\n15 + 20 = ________\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a027 + 20 = __________<br \/>\n15 + 30 = ________\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a027 + 30 = __________<br \/>\nAnswer:<br \/>\n15 + 10 = ___25_____\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a027 + 10 = ___37_______<br \/>\n15 + 20 = ___35_____\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a027 + 20 = ____47______<br \/>\n15 + 30 = _____45___\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a027 + 30 = ___57_______<\/p>\n<p>Explanation:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33604\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.8-Add-Tens-to-a-Number-Explore-and-Grow.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Lesson-8.8-Add-Tens-to-a-Number-Explore and Grow\" width=\"548\" height=\"350\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.8-Add-Tens-to-a-Number-Explore-and-Grow.png 548w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.8-Add-Tens-to-a-Number-Explore-and-Grow-300x192.png 300w\" sizes=\"(max-width: 548px) 100vw, 548px\" \/><\/p>\n<p><strong>Show and Grow<\/strong><\/p>\n<p>Question 1.<br \/>\n23 + 50 = ____________<br \/>\nAnswer:<br \/>\n23 + 50 =\u00a0 73.<\/p>\n<p>Question 2.<br \/>\n6 + 70 = ____________<br \/>\nAnswer:<br \/>\n6 + 70 = 76.<\/p>\n<p><strong>Apply and Grow: practice<\/strong><\/p>\n<p>Question 3.<br \/>\n27 + 40 = ____________<br \/>\nAnswer:<br \/>\n27 + 40 = 67.<\/p>\n<p>Question 4.<br \/>\n8 + 80 = ____________<br \/>\nAnswer:<br \/>\n8 + 80 = 88.<\/p>\n<p>Question 5.<br \/>\n60 + 35 = ____________<br \/>\nAnswer:<br \/>\n60 + 35 =\u00a0 95.<\/p>\n<p>Question 6.<br \/>\n30 + 44 = ____________<br \/>\nAnswer:<br \/>\n30 + 44 = 74.<\/p>\n<p>Question 7.<br \/>\n____________ = 33 + 20<br \/>\nAnswer:<br \/>\n53 = 33 + 20.<\/p>\n<p>Question 8.<br \/>\n____________ = 70 + 22<br \/>\nAnswer:<br \/>\n92= 70 + 22.<\/p>\n<p>Question 9.<br \/>\n<strong>YOU BE THE TEACHER<\/strong><br \/>\nIs Newton correct? Explain.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-27444\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-69.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 8 Add and Subtract Tens 69\" width=\"476\" height=\"165\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-69.png 476w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-69-300x104.png 300w\" sizes=\"(max-width: 476px) 100vw, 476px\" \/><br \/>\nAnswer:<br \/>\n36 +50 = 86.<br \/>\nNewton is correct.<\/p>\n<p>Explanation:<br \/>\n36 +50 = 86.<br \/>\nHence, Newton is correct because the addition of both the addends is correct.<\/p>\n<p><strong>Think and Grow: Modeling Real Life<\/strong><\/p>\n<p>You count 8 birds on your way to school. You count 40 more on your way home. Your friend counts 45 birds in all. Who counts more birds?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-27443\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-70.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 8 Add and Subtract Tens 70\" width=\"171\" height=\"135\" \/><br \/>\nModel:<\/p>\n<p>Addition equation:<\/p>\n<p>Compare: ___________ \u25cb ____________<\/p>\n<p>Who counts more birds?\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 You\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0Friend<\/p>\n<p>Answer:<br \/>\nI have counted 3 birds more than my friend.<\/p>\n<p>Explanation:<br \/>\nNumber of birds I counted on the way to school = 8<br \/>\nNumber of birds I counted more on your way home = 40<br \/>\nTotal number of birds my friend counts in all = 45<br \/>\nTotal number of birds I counted in all = Number of birds I counted on the way to school &#8211; Number of birds I counted more on your way home<br \/>\n= 8 + 40<br \/>\n= 48.<\/p>\n<p>Comparison:<br \/>\nNumber of birds who counted more = Total number of birds I counted in all &#8211; Total number of birds my friend counts in all<br \/>\n= 48 &#8211; 45<br \/>\n= 3<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33981\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-8.6-Show-and-Grow8-and-Grow-Real-Life-1.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-8.6-Show-and-Grow8--and-Grow-Real-Life\" width=\"239\" height=\"90\" \/><\/p>\n<p>Hence, I have counted 3 birds more than my friend.<\/p>\n<p><strong>Show and Grow<\/strong><\/p>\n<p>Question 10.<br \/>\nYou make 21 snowballs. Your friend makes 11 small snowballs and 20 large snowballs. Who makes more snowballs?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-27442\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-71.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 8 Add and Subtract Tens 71\" width=\"220\" height=\"148\" \/><br \/>\nModel:<\/p>\n<p>Addition equation:<\/p>\n<p>Compare: ___________ \u25cb ____________<\/p>\n<p>Who counts more birds?\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 You\u00a0 \u00a0 \u00a0 Friend<br \/>\nAnswer:<br \/>\nNumber of snow balls who made more = 10.<\/p>\n<p>Explanation:<br \/>\nTotal number of snow balls I made = 21<br \/>\nTotal number of small snow balls my friend made =11<br \/>\nTotal number of large snow balls my friend made = 20<br \/>\nTotal number of snow balls my friend made = Total number of small snow balls my friend made + Total number of large snow balls my friend made<br \/>\n= 11 + 20<br \/>\n= 31<\/p>\n<p>Comparison:<br \/>\nNumber of snow balls who made more = Total number of snow balls my friend made &#8211; Total number of snow balls I made<br \/>\n=\u00a0 31 &#8211; 21<br \/>\n= 10.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33983\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-8.6-Show-and-Grow10.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-8.6-Show and Grow10\" width=\"195\" height=\"92\" \/><br \/>\nHence, the Number of snow balls who made more = 10.<\/p>\n<h3><a id=\"Add_Tens_to_a_Number_Practice_8.8\"><\/a>Add Tens to a Number Practice 8.8<\/h3>\n<p>Question 1.<br \/>\n19 + 40 = __________<br \/>\nAnswer:<br \/>\n19 + 40 = 59.<\/p>\n<p>Question 2.<br \/>\n60 + 23 = __________<br \/>\nAnswer:<br \/>\n60 + 23 = 83.<\/p>\n<p>Question 3.<br \/>\n__________ = 5 + 90<br \/>\nAnswer:<br \/>\n95 = 5 + 90.<\/p>\n<p>Question 4.<br \/>\n__________ = 37 + 30<br \/>\nAnswer:<br \/>\n67 = 37 + 30.<\/p>\n<p>Question 5.<br \/>\n<strong>YOU BE THE TEACHER<\/strong><br \/>\nIs Descartes correct? Explain.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-27441\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-72.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 8 Add and Subtract Tens 72\" width=\"486\" height=\"163\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-72.png 486w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-72-300x101.png 300w\" sizes=\"(max-width: 486px) 100vw, 486px\" \/><br \/>\nAnswer:<br \/>\nDescartes is incorrect.<\/p>\n<p>Explanation:<br \/>\n46 + 20 = 66.<br \/>\nHence, Descartes is incorrect because he did not do the addition correctly.<\/p>\n<p>Question 6.<br \/>\n<strong>Modeling Real Life<\/strong><br \/>\nYou have 24 glow sticks and buy 40 more. Your friend has 66 glow sticks. Who has more glow sticks?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-27440\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-73.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 8 Add and Subtract Tens 73\" width=\"117\" height=\"79\" \/><\/p>\n<p>Who has more glow sticks?\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0You\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0Friend<\/p>\n<p>Answer:<br \/>\nMy friend has 2 glow sticks more than me.<\/p>\n<p>Explanation:<br \/>\nNumber of glow sticks I have = 24<br \/>\nNumber of glow sticks I have purchased more = 40<br \/>\nTotal number of glow sticks I have = Number of glow sticks I have + Number of glow sticks I have purchased more<br \/>\n= 24 + 40<br \/>\n= 64<br \/>\nNumber of \u00a0glow sticks my friend has = 66<br \/>\nComparison:<br \/>\nNumber of \u00a0glow sticks who has more = Number of \u00a0glow sticks my friend has &#8211; Total number of glow sticks I have<br \/>\n= 66 &#8211; 64<br \/>\n= 2<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33985\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-8.6-Show-and-Grow-Modeling-Real-Life6.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-8.6-Show and Grow-Modeling Real Life6\" width=\"204\" height=\"96\" \/><br \/>\nHence, my friend has 2 glow sticks more than me.<\/p>\n<p><strong>Review &amp; Refresh<\/strong><\/p>\n<p>Question 7.<br \/>\nCircle the solid shapes that stack.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-27439\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-74.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 8 Add and Subtract Tens 74\" width=\"401\" height=\"86\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-74.png 401w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-74-300x64.png 300w\" sizes=\"(max-width: 401px) 100vw, 401px\" \/><\/p>\n<p>Answer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33606\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.8-Add-Tens-to-a-Number-Review-Refresh7-1.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Lesson-8.8-Add-Tens-to-a-Number-Review &amp; Refresh7\" width=\"494\" height=\"177\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.8-Add-Tens-to-a-Number-Review-Refresh7-1.png 494w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Lesson-8.8-Add-Tens-to-a-Number-Review-Refresh7-1-300x107.png 300w\" sizes=\"(max-width: 494px) 100vw, 494px\" \/><\/p>\n<p>Explanation:<br \/>\nIn Geometry, Solids are three-dimensional shapes because they have three dimensions such as length, breadth and height. The bodies which occupy space are called solids.<br \/>\nhere in the above picture, cone , cylinder ,cube are solid shapes that stack not sphere shape ball.<\/p>\n<h3><a id=\"Add_and_Subtract_Tens_Performance_Task\"><\/a>Add and Subtract Tens Performance Task<\/h3>\n<p>Question 1.<br \/>\nThe tables show the numbers of seconds 3 pinwheels and 3 fops spin.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-27574\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-75.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 8 Add and Subtract Tens 75\" width=\"529\" height=\"169\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-75.png 529w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-75-300x96.png 300w\" sizes=\"(max-width: 529px) 100vw, 529px\" \/><\/p>\n<p>a. How many more seconds does the yellow top spin than the red pinwheel?<br \/>\n__________ seconds<br \/>\nAnswer:<br \/>\nNumber of more seconds the yellow top spin than the red pinwheel taken = 50.<\/p>\n<p>Explanation:<br \/>\nNumber of seconds red pinwheel taken =\u00a0 40<br \/>\nNumber of seconds yellow pinwheel taken = 90<br \/>\nNumber of more seconds the yellow top spin than the red pinwheel taken = Number of seconds red pinwheel taken &#8211; Number of seconds yellow pinwheel taken<br \/>\n= 90 &#8211; 40<br \/>\n= 50.<br \/>\nHence, Number of more seconds the yellow top spin than the red pinwheel taken = 50.<\/p>\n<p>b. The red pinwheel spins 30 fewer seconds than the red top. How long does the red top spin?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-27573\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-76.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 8 Add and Subtract Tens 76\" width=\"65\" height=\"65\" \/><br \/>\n__________ seconds<br \/>\nAnswer:<br \/>\nThe number of seconds the red top taken = 70.<\/p>\n<p>Explanation:<br \/>\nNumber of seconds the red pinwheels spins = 40<br \/>\nLet the number of seconds the red top taken be X<br \/>\nThe number of seconds the red top taken &#8211; 30 =\u00a0 Number of seconds the red pinwheels spins<br \/>\n(The red pinwheel spins 30 fewer seconds than the red top)<br \/>\n=&gt;\u00a0 X &#8211; 30 = 40<br \/>\n=&gt; X = 40 + 30<br \/>\n=&gt; X = 70<br \/>\nHence, The number of seconds the red top taken = 70.<\/p>\n<p>c. The blue pinwheel and the blue top spin for 96 seconds in all. How long does the blue pinwheel spin?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-27572\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-8-Add-and-Subtract-Tens-77.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 8 Add and Subtract Tens 77\" width=\"37\" height=\"68\" \/><br \/>\n__________ seconds<br \/>\nAnswer:<br \/>\nNumber of seconds blue\u00a0 pinwheel spin taken = 60.<\/p>\n<p>Explanation:<br \/>\nNumber of seconds blue top spin taken = 36<br \/>\nTotal number of seconds the blue pinwheel and the blue top spins = 96<br \/>\nNumber of seconds blue pinwheel spin taken = Number of seconds blue top spin taken &#8211; Total number of seconds the blue pinwheel and the blue top spins<br \/>\n= 96 &#8211; 36<br \/>\n= 60.<br \/>\nHence, Number of seconds blue pinwheel spin taken = 60.<\/p>\n<p>d. Which pinwheel spins the longest?<br \/>\nRed\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0Yellow\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0Blue<br \/>\nAnswer:<br \/>\nThe yellow pinwheel spins the longest than other pinwheels.<\/p>\n<p>Explanation:<br \/>\nNumber of seconds blue pinwheel spin taken = 60<br \/>\nNumber of seconds yellow pinwheel spin taken = 90<br \/>\nNumber of seconds red pinwheel spin taken = 40<br \/>\nAmong, the three pinwheels, the yellow pinwheel spins the longest than other pinwheels.<\/p>\n<h3><a id=\"Add_and_Subtract_Tens_Chapter_Practice\"><\/a>Add and Subtract Tens Chapter Practice<\/h3>\n<h3>Mental Math: 10 More Homework &amp; Practice 8.1<\/h3>\n<p>Use mental math.<\/p>\n<p>Question 1.<br \/>\n58 + 10 = ___________<br \/>\nAnswer:<br \/>\n58 + 10 = 68.<\/p>\n<p>Question 2.<br \/>\n15 + 10 = ___________<br \/>\nAnswer:<br \/>\n15 + 10 = 25.<\/p>\n<p>Question 3.<br \/>\n29 + 10 = ___________<br \/>\nAnswer:<br \/>\n29 + 10 = 39.<\/p>\n<p>Question 4.<br \/>\n41 + 10 = ___________<br \/>\nAnswer:<br \/>\n41 + 10 = 51.<\/p>\n<p>Question 5.<br \/>\n10 + 7 = ___________<br \/>\nAnswer:<br \/>\n10 + 7 =\u00a0 17.<\/p>\n<p>Question 6.<br \/>\n10 + 36 = ___________<br \/>\nAnswer:<br \/>\n10 + 36 = 46.<\/p>\n<p>Question 7.<br \/>\n84 + ___________ = 94<br \/>\nAnswer:<br \/>\n84 + 10= 94<\/p>\n<p>Explanation:<br \/>\nLet the missing number be X.<br \/>\nAdd the addends.<br \/>\n84 + X = 94<br \/>\nX = 94 &#8211; 84<br \/>\nX = 10.<\/p>\n<p>Question 8.<br \/>\n47 + ___________ = 57<br \/>\nAnswer:<br \/>\n47 + 10 = 57.<br \/>\nExplanation:<br \/>\nLet the missing number be X.<br \/>\nadd the addends.<br \/>\n47 + X = 57<br \/>\nX = 57 &#8211; 47<br \/>\nX =10.<\/p>\n<h3>Mental Math: 10 Less Homework &amp; Practice 8.2<\/h3>\n<p>Use mental math.<\/p>\n<p>Question 9.<br \/>\n24 &#8211; 10 = ___________<br \/>\nAnswer:<br \/>\n24 &#8211; 10 = 14.<\/p>\n<p>Question 10.<br \/>\n78 &#8211; 10 = ___________<br \/>\nAnswer:<br \/>\n78 &#8211; 10 =\u00a0 68.<\/p>\n<p>Question 11.<br \/>\n31 &#8211; 10 = ___________<br \/>\nAnswer:<br \/>\n31 &#8211; 10 = 21.<\/p>\n<p>Question 12.<br \/>\n95 &#8211; 10 = ___________<br \/>\nAnswer:<br \/>\n95 &#8211; 10 = 85.<\/p>\n<p>Question 13.<br \/>\n___________ &#8211; 10 = 7<br \/>\nAnswer:<br \/>\n17 &#8211; 10 = 7.<\/p>\n<p>Explanation:<br \/>\nLet the Missing minuend be X.<br \/>\nSubtrahend = 10<br \/>\nDifference = 7<br \/>\nSubtract the numbers:<br \/>\nX &#8211; 10 = 7<br \/>\nX = 7 + 10<br \/>\nX = 17.<br \/>\nHence, 17 &#8211; 10 = 7.<\/p>\n<p>Question 14.<br \/>\n___________ &#8211; 10 = 43<br \/>\nAnswer:<br \/>\n53 &#8211; 10 = 43.<\/p>\n<p>Explanation:<br \/>\nLet the Missing minuend be X.<br \/>\nSubtrahend = 10<br \/>\nDifference = 43<br \/>\nSubtract the numbers:<br \/>\nX &#8211; 10 = 43<br \/>\nX = 43 + 10<br \/>\nX = 53.<br \/>\nHence, 53 &#8211; 10 = 43.<\/p>\n<h3>Add Tens Homework &amp; Practice 8.3<\/h3>\n<p>Question 15.<br \/>\n60 + 20 = ?<br \/>\n__________ tens + ___________ tens = ___________ tens<br \/>\nSo, 60 + 20 = ___________ .<br \/>\nAnswer:<br \/>\n60 + 20 = 80.<\/p>\n<p>Explanation:<br \/>\n_______6___ tens + _______2____ tens = ______8_____ tens<br \/>\nSo, 60 + 20 = _____80______ .<\/p>\n<p>Question 16.<br \/>\n30 + 50 = ___________<br \/>\nAnswer:<br \/>\n30 + 50 = 80.<\/p>\n<p>Question 17.<br \/>\n___________ + 30 = 90<br \/>\nAnswer:<br \/>\n60 + 30 = 90.<\/p>\n<p>Explanation:<br \/>\nLet the missing addend be X.<br \/>\nsum = 90<br \/>\nAdd the numbers<br \/>\nX + 30= 90<br \/>\nX = 90\u00a0 &#8211; 30<br \/>\nX = 60.<br \/>\nHence, 60 + 30 = 90.<\/p>\n<h3>Add Tens Using a Number Line Homework &amp; Practice 8.4<\/h3>\n<p>Question 18.<br \/>\n50 + 40 = ___________<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-27697\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-8-Add-and-Subtract-Tens-78.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 8 Add and Subtract Tens 78\" width=\"424\" height=\"45\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-8-Add-and-Subtract-Tens-78.png 424w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-8-Add-and-Subtract-Tens-78-300x32.png 300w\" sizes=\"(max-width: 424px) 100vw, 424px\" \/><br \/>\nAnswer:<br \/>\n50 + 40 = 90.<\/p>\n<p>Explanation:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33614\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Add-Tens-Using-a-Number-Line-Homework-Practice-8.4.18.png\" alt=\"\" width=\"802\" height=\"176\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Add-Tens-Using-a-Number-Line-Homework-Practice-8.4.18.png 802w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Add-Tens-Using-a-Number-Line-Homework-Practice-8.4.18-300x66.png 300w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Add-Tens-Using-a-Number-Line-Homework-Practice-8.4.18-768x169.png 768w\" sizes=\"(max-width: 802px) 100vw, 802px\" \/><\/p>\n<p>Question 19.<br \/>\n<strong>MP Structure<\/strong><br \/>\nWrite an equation that matches the number line.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-27696\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-8-Add-and-Subtract-Tens-79.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 8 Add and Subtract Tens 79\" width=\"423\" height=\"145\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-8-Add-and-Subtract-Tens-79.png 423w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-8-Add-and-Subtract-Tens-79-300x103.png 300w\" sizes=\"(max-width: 423px) 100vw, 423px\" \/><br \/>\nAnswer:<br \/>\nEquation:<br \/>\n20 + 30 =50.<\/p>\n<p>Explanation:<br \/>\n20 + 10 +10 +10<br \/>\n= 30 +10 +10<br \/>\n= 40 + 10<br \/>\n= 50.<\/p>\n<h3>Subtract Tens Homework &amp; Practice 8.5<\/h3>\n<p>Question 20.<br \/>\n90 &#8211; 40 = ?<br \/>\n__________ tens &#8211; ___________ tens = ___________ tens<br \/>\nSo, 90 &#8211; 40 = ___________ .<br \/>\nAnswer:<br \/>\n90 &#8211; 40 = 50.<\/p>\n<p>Explanation:<br \/>\n___9__tens &#8211; __4_____ tens = ______5_____ tens<br \/>\nSo, 90 &#8211; 40 = _50__________ .<\/p>\n<p>Question 21.<br \/>\n70 &#8211; 40 = ___________<br \/>\nAnswer:<br \/>\n70 &#8211; 40 = 20.<\/p>\n<p>Question 22.<br \/>\n80 &#8211; __________ = 60<br \/>\nAnswer:<br \/>\n80 &#8211; 20 = 60.<\/p>\n<p>Explanation:<br \/>\nLet the missing number be X.<br \/>\nAdd the addends.<br \/>\n80 &#8211; X = 60<br \/>\n80 = 60 + X<br \/>\n80 &#8211; 60 = X<br \/>\n20 = X.<\/p>\n<h3>Subtract Tens Using a Number Line Homework &amp; Practice 8.6<\/h3>\n<p>Question 23.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-27695\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-8-Add-and-Subtract-Tens-80.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 8 Add and Subtract Tens 80\" width=\"426\" height=\"42\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-8-Add-and-Subtract-Tens-80.png 426w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-8-Add-and-Subtract-Tens-80-300x30.png 300w\" sizes=\"(max-width: 426px) 100vw, 426px\" \/><br \/>\n60 &#8211; 40 = __________<br \/>\nAnswer:<br \/>\n60 &#8211; 40 = 20.<\/p>\n<p>Explanation:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33612\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Subtract-Tens-Using-a-Number-Line-Homework-Practice-8.6.23-1.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Subtract-Tens-Using-a-Number- Line- Homework &amp; Practice 8.6.23\" width=\"657\" height=\"127\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Subtract-Tens-Using-a-Number-Line-Homework-Practice-8.6.23-1.png 657w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Subtract-Tens-Using-a-Number-Line-Homework-Practice-8.6.23-1-300x58.png 300w\" sizes=\"(max-width: 657px) 100vw, 657px\" \/><\/p>\n<p>Question 24.<br \/>\n<strong>MP Structure<\/strong><br \/>\nWrite the equation that matches the number line.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-27694\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-8-Add-and-Subtract-Tens-81.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 8 Add and Subtract Tens 81\" width=\"426\" height=\"146\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-8-Add-and-Subtract-Tens-81.png 426w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-8-Add-and-Subtract-Tens-81-300x103.png 300w\" sizes=\"(max-width: 426px) 100vw, 426px\" \/><br \/>\nAnswer:<br \/>\nEquation: 70 &#8211;\u00a0 20 = 50.<\/p>\n<p>Explanation:<br \/>\nNumber line representation :<br \/>\n70 &#8211; 10 -10<br \/>\n= 60 -10<br \/>\n= 50.<\/p>\n<h3>Use Addition to Subtract Tens Homework &amp; Practice 8.7<\/h3>\n<p>Question 25.<br \/>\n80 &#8211; 60 = ?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-27693\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-8-Add-and-Subtract-Tens-82.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 8 Add and Subtract Tens 82\" width=\"426\" height=\"47\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-8-Add-and-Subtract-Tens-82.png 426w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-8-Add-and-Subtract-Tens-82-300x33.png 300w\" sizes=\"(max-width: 426px) 100vw, 426px\" \/><br \/>\nThink 60 + __________ = 80<br \/>\nSo, 80 &#8211; 60 = __________ .<br \/>\nAnswer:<br \/>\n80 &#8211; 60 = 20.<\/p>\n<p>Explanation:<\/p>\n<p><img loading=\"lazy\" class=\"alignnone size-full wp-image-33608\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Use-Addition-to-Subtract-Tens-Homework-Practice-8.7-25.png\" alt=\"Big-Ideas-Math-Answers-Grade-1-Chapter 8-Add-and-Subtract-Tens-Use-Addition-to-Subtract-Tens-Homework- &amp;- Practice 8.7-25\" width=\"526\" height=\"113\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Use-Addition-to-Subtract-Tens-Homework-Practice-8.7-25.png 526w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-8-Add-and-Subtract-Tens-Use-Addition-to-Subtract-Tens-Homework-Practice-8.7-25-300x64.png 300w\" sizes=\"(max-width: 526px) 100vw, 526px\" \/><br \/>\nThink 60 + ____20______ = 80<br \/>\nSo, 80 &#8211; 60 = _____20_____ .<\/p>\n<p>Question 26.<br \/>\n<strong>Modeling Real Life<\/strong><br \/>\nA mail carrier has 90 packages to deliver. She delivers 60 of them. How many packages are left?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-27692\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-8-Add-and-Subtract-Tens-83.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 8 Add and Subtract Tens 83\" width=\"53\" height=\"107\" \/><br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-27691\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-8-Add-and-Subtract-Tens-84.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 8 Add and Subtract Tens 84\" width=\"425\" height=\"26\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-8-Add-and-Subtract-Tens-84.png 425w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-8-Add-and-Subtract-Tens-84-300x18.png 300w\" sizes=\"(max-width: 425px) 100vw, 425px\" \/><\/p>\n<p>______________ packages<br \/>\nAnswer:<br \/>\nNumber of packages left = 30.<\/p>\n<p>Explanation:<br \/>\nNumber of packages are there for deliver = 90<br \/>\nnumber of packages she delivered = 60<br \/>\nNumber of packages left = Number of packages are there for deliver &#8211; number of packages she delivered<br \/>\n= 90 &#8211; 60<br \/>\n= 30.<br \/>\nHence, Number of packages left = 30.<\/p>\n<h3>Add Tens to a Number Homework &amp; Practice 8.8<\/h3>\n<p>Question 27.<br \/>\n27 + 50 = ____________<br \/>\nAnswer:<br \/>\n27 + 50 = 77.<\/p>\n<p>Question 28.<br \/>\n_____________ = 80 + 12<br \/>\nAnswer:<br \/>\n92 = 80 + 12.<\/p>\n<p><em>Conclusion:<\/em><\/p>\n<p>You can know how to use the number line in a simple method from our Big Ideas Math Book 1st Grade Answer Key Chapter 8 Add and Subtract Tens. Learn the fundamentals of maths like addition and subtraction from this page. Bookmark our page to get the Answer Key of all Big Ideas Math Grade 1 Chapters from 1 to 14.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Big Ideas Math Book 1st Grade Answer Key Chapter 8 Add and Subtract Tens helps the students to overcome the difficulties in math. Learning in a fun way will make maths more interesting to students. You can see step-by-step explanations for all the questions by using the figures. You can easily understand the concepts deeply &#8230; <a title=\"Big Ideas Math Answers Grade 1 Chapter 8 Add and Subtract Tens\" class=\"read-more\" href=\"https:\/\/bigideasmathanswers.com\/big-ideas-math-answers-grade-1-chapter-8\/\" aria-label=\"More on Big Ideas Math Answers Grade 1 Chapter 8 Add and Subtract Tens\">Read more<\/a><\/p>\n","protected":false},"author":9,"featured_media":89534,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"spay_email":""},"categories":[4],"tags":[],"jetpack_featured_media_url":"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/04\/Big-Ideas-Math-Answers-Grade-1-Chapter-8.png","_links":{"self":[{"href":"https:\/\/bigideasmathanswers.com\/wp-json\/wp\/v2\/posts\/26684"}],"collection":[{"href":"https:\/\/bigideasmathanswers.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/bigideasmathanswers.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/bigideasmathanswers.com\/wp-json\/wp\/v2\/users\/9"}],"replies":[{"embeddable":true,"href":"https:\/\/bigideasmathanswers.com\/wp-json\/wp\/v2\/comments?post=26684"}],"version-history":[{"count":1,"href":"https:\/\/bigideasmathanswers.com\/wp-json\/wp\/v2\/posts\/26684\/revisions"}],"predecessor-version":[{"id":90314,"href":"https:\/\/bigideasmathanswers.com\/wp-json\/wp\/v2\/posts\/26684\/revisions\/90314"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/bigideasmathanswers.com\/wp-json\/wp\/v2\/media\/89534"}],"wp:attachment":[{"href":"https:\/\/bigideasmathanswers.com\/wp-json\/wp\/v2\/media?parent=26684"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/bigideasmathanswers.com\/wp-json\/wp\/v2\/categories?post=26684"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/bigideasmathanswers.com\/wp-json\/wp\/v2\/tags?post=26684"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}