{"id":24645,"date":"2022-04-03T15:49:53","date_gmt":"2022-04-03T10:19:53","guid":{"rendered":"https:\/\/ccssmathanswers.com\/?p=24645"},"modified":"2022-04-07T11:29:43","modified_gmt":"2022-04-07T05:59:43","slug":"big-ideas-math-answers-grade-1-chapter-5","status":"publish","type":"post","link":"https:\/\/bigideasmathanswers.com\/big-ideas-math-answers-grade-1-chapter-5\/","title":{"rendered":"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20"},"content":{"rendered":"<p>Enhance your subject knowledge by taking the help of the Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20. Practice Big Ideas Math Book 1st Grade Answer Key Chapter 5 Subtract Numbers within 20 and answer the questions from the chapter with confidence. The detailed explanation provided helps you understand the topics easily. Become champ in the subject by referring to our <a href=\"https:\/\/bigideasmathanswers.com\/big-ideas-math-answers-grade-1\/\">Big Ideas Math Answers Grade 1<\/a> Chapter 5 Subtract Numbers within 20.<\/p>\n<h2>Big Ideas Math Book 1st Grade Answer Key Chapter 5 Subtract Numbers within 20<\/h2>\n<p>Attain the logic behind each problem in the exercise questions from Big Ideas Math Book 1st Grade Answer Key Chapter 5 Subtract Numbers within 20 and clear the exam with better grades. Have an overview of the concepts present in Bigideas Math Grade 1 Chapter 5 Subtract Numbers within 20 Answer Key through the quick links available. Utilize the Grade 1 Big Ideas Math Answers Chapter 5 Subtract Numbers within 20 Use Multiplication Facts and clear your queries regarding the topics instantly. You just need to click on the below-mentioned links and take your preparation to the next level.<\/p>\n<p><strong>Vocabulary<\/strong><\/p>\n<ul>\n<li><a href=\"#Chapter_5_Subtract_Numbers_within_20_Vocabulary\">Chapter 5 Subtract Numbers within 20 Vocabulary<\/a><\/li>\n<\/ul>\n<p><strong>Lesson: 1 Count Back to Subtract within 20<\/strong><\/p>\n<ul>\n<li><a href=\"#Lesson_5.1_Count_Back_to_Subtract_within_20\">Lesson 5.1 Count Back to Subtract within 20<\/a><\/li>\n<li><a href=\"#Count_Back_to_Subtract_within_20_Practice_5.1\">Count Back to Subtract within 20 Practice 5.1<\/a><\/li>\n<\/ul>\n<p><strong>Lesson: 2 Use Addition to Subtract within 20<\/strong><\/p>\n<ul>\n<li><a href=\"#Lesson_5.2_Use_Addition_to_Subtract_within_20\">Lesson 5.2 Use Addition to Subtract within 20<\/a><\/li>\n<li><a href=\"#Use_Addition_to_Subtract_within_20_Practice_5.2\">Use Addition to Subtract within 20 Practice 5.2<\/a><\/li>\n<\/ul>\n<p><strong>Lesson: 3 Subtract 9<\/strong><\/p>\n<ul>\n<li><a href=\"#Lesson_5.3_Subtract_9\">Lesson 5.3 Subtract 9<\/a><\/li>\n<li><a href=\"#Subtract_9_Practice_5.3\">Subtract 9 Practice 5.3<\/a><\/li>\n<\/ul>\n<p><strong>Lesson: 4 Get to 10 to Subtract<\/strong><\/p>\n<ul>\n<li><a href=\"#Lesson_5.4_Get_to_10_to_Subtract\">Lesson 5.4 Get to 10 to Subtract<\/a><\/li>\n<li><a href=\"#Get_to_10_to_Subtract_Practice_5.4\">Get to 10 to Subtract Practice 5.4<\/a><\/li>\n<\/ul>\n<p><strong>Lesson: 5 More True or False Equations<\/strong><\/p>\n<ul>\n<li><a href=\"#Lesson_5.5_More_True_or_False_Equations\">Lesson 5.5 More True or False Equations<\/a><\/li>\n<li><a href=\"#More_True_or_False_Equations_Homework_&amp;_Practice_5.5\">More True or False Equations Homework &amp; Practice 5.5<\/a><\/li>\n<\/ul>\n<p><strong>Lesson: 6 Make True Equations<\/strong><\/p>\n<ul>\n<li><a href=\"#Lesson_5.6_Make_True_Equations\">Lesson 5.6 Make True Equations<\/a><\/li>\n<li><a href=\"#Make_True_Equations_Practice_5.6\">Make True Equations Homework &amp; Practice 5.6<\/a><\/li>\n<\/ul>\n<p><strong>Lesson: 7 Problem Solving: Subtraction within 20<\/strong><\/p>\n<ul>\n<li><a href=\"#Lesson_5.7_Problem_Solving:_Subtraction_within_20\">Lesson 5.7 Problem Solving: Subtraction within 20<\/a><\/li>\n<li><a href=\"#Problem_Solving:_Subtraction_within_20_Practice_5.7\">Problem Solving: Subtraction within 20 Practice 5.7<\/a><\/li>\n<\/ul>\n<p><strong>Chapter 5 Subtract Numbers within 20<\/strong><\/p>\n<ul>\n<li><a href=\"#Chapter_5_Subtract_Numbers_within_20_Performance_Task\">Chapter 5 Subtract Numbers within 20 Performance Task<\/a><\/li>\n<li><a href=\"#Chapter_5_Subtract_Numbers_within_20_Chapter_Practice\">Chapter 5 Subtract Numbers within 20 Chapter Practice<\/a><\/li>\n<\/ul>\n<h3><a id=\"Chapter_5_Subtract_Numbers_within_20_Vocabulary\"><\/a>Chapter 5 Subtract Numbers within 20 Vocabulary<\/h3>\n<p><strong>Organize It<\/strong><\/p>\n<p>Review Words:<br \/>\nbar model<br \/>\ndifference<br \/>\nminus<br \/>\npart-part-whole model<br \/>\nsubtraction equation<\/p>\n<p>Use the review words to complete the graphic organizer.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24647\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-1.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 1\" width=\"444\" height=\"184\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-1.png 444w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-1-300x124.png 300w\" sizes=\"(max-width: 444px) 100vw, 444px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-29958 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-1.bmp\" alt=\"\" width=\"444\" height=\"184\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-1.bmp 444w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-1-300x124.jpg 300w\" sizes=\"(max-width: 444px) 100vw, 444px\" \/><\/p>\n<p>Explanation:<br \/>\nGiven 8 &#8211; 3 = 5, Here &#8211; represents minus sign minus<br \/>\nrepresents the arithmetic operation of subtraction between<br \/>\ntwo numbers, 5 represents difference is the result of subtracting<br \/>\none number from another and 8 &#8211; 3 = 5 is called subtraction equation<b><br \/>\n<\/b>\u00a0is a statement that shows a\u00a0subtraction\u00a0operation using the minuend,<br \/>\nsubtrahend, difference.<\/p>\n<p><strong>Define It<\/strong><\/p>\n<p>Match the review word to its definition.<\/p>\n<p><img loading=\"lazy\" class=\"alignnone size-full wp-image-24646\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-2.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 2\" width=\"485\" height=\"221\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-2.png 485w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-2-300x137.png 300w\" sizes=\"(max-width: 485px) 100vw, 485px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-29963 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-2.bmp\" alt=\"\" width=\"485\" height=\"221\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-2.bmp 485w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-2-300x137.jpg 300w\" sizes=\"(max-width: 485px) 100vw, 485px\" \/><\/p>\n<p>Explanation:<br \/>\nIn the above picture, the first one is a bar model\u00a0 a pictorial representation<br \/>\nof a problem or concept where bars or boxes are used to represent the<br \/>\nknown and unknown quantities, the second picture is the part-part-whole model<br \/>\nis a simple pictorial representation of a problem that helps us<br \/>\nsee the relationships between numbers.<\/p>\n<h3><a id=\"Lesson_5.1_Count_Back_to_Subtract_within_20\"><\/a>Lesson 5.1 Count Back to Subtract within 20<\/h3>\n<p><strong>Explore and Grow<\/strong><\/p>\n<p>Model the story.<\/p>\n<p>You are on floor number 12. You go down 4 floors. What floor are you on now?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24666\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-3.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 3\" width=\"94\" height=\"100\" \/><\/p>\n<p><img loading=\"lazy\" class=\"alignnone size-full wp-image-24665\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-4.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 4\" width=\"425\" height=\"54\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-4.png 425w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-4-300x38.png 300w\" sizes=\"(max-width: 425px) 100vw, 425px\" \/><\/p>\n<p>floor number ____8______<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-29967 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-2-1.bmp\" alt=\"\" width=\"445\" height=\"175\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-2-1.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-2-1-300x118.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><br \/>\nI am in 8 floors now.<\/p>\n<p>Explanation:<br \/>\nGiven I am on floor number 12 and go down 4 floors means<br \/>\nnow I am on floor 12 &#8211; 4 = 8 . on the number line we start from 12<br \/>\nsince subtracting makes numbers smaller, we move left to subtract.<br \/>\nSo from 12 we move 4 parts back or left to 8. Therefore now I am at<br \/>\n8 floor now.<\/p>\n<p><strong>Show and Grow<\/strong><\/p>\n<p>Question 1.<br \/>\n15 &#8211; 8 = ___7____<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24664\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-5.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 5\" width=\"424\" height=\"43\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-5.png 424w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-5-300x30.png 300w\" sizes=\"(max-width: 424px) 100vw, 424px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-29968 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-3.bmp\" alt=\"\" width=\"445\" height=\"175\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-3.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-3-300x118.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><br \/>\n15 &#8211; 8 = 7<\/p>\n<p>Explanation:<br \/>\nWe subtract 15 &#8211; 8 = 7, on number line we start at 15 and<br \/>\nmove 8 steps back or left we get 7.<\/p>\n<p>Question 2.<br \/>\n12 &#8211; 3 = ___9______<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24663\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-6.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 6\" width=\"423\" height=\"39\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-6.png 423w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-6-300x28.png 300w\" sizes=\"(max-width: 423px) 100vw, 423px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-29969 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-4.bmp\" alt=\"\" width=\"445\" height=\"175\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-4.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-4-300x118.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><br \/>\n12- 3 = 9<\/p>\n<p>Explanation:<br \/>\nWe subtract 12 &#8211; 3 = 9, on number line we start at 12 and<br \/>\nmove 3 steps back or left we get 9.<\/p>\n<p>Question 3.<br \/>\n17 &#8211; 9 = ____8_____<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24663\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-6.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 6\" width=\"423\" height=\"39\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-6.png 423w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-6-300x28.png 300w\" sizes=\"(max-width: 423px) 100vw, 423px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-29970 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-4-1.bmp\" alt=\"\" width=\"445\" height=\"175\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-4-1.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-4-1-300x118.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><br \/>\n17 &#8211; 9 = 8<\/p>\n<p>Explanation:<br \/>\nWe subtract 17 &#8211; 9 = 8, on the number line we start at 17 and<br \/>\nmove 9 steps back or left we get 8.<\/p>\n<p><strong>Apply and Grow: Practice<\/strong><\/p>\n<p>Question 4.<br \/>\n11 &#8211; 6 = ____5____<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24663\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-6.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 6\" width=\"423\" height=\"39\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-6.png 423w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-6-300x28.png 300w\" sizes=\"(max-width: 423px) 100vw, 423px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-29971 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-5.bmp\" alt=\"\" width=\"445\" height=\"175\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-5.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-5-300x118.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><br \/>\n11 &#8211; 6 = 5<\/p>\n<p>Explanation:<br \/>\nWe subtract 11 &#8211; 6 = 5, on the number line we start at 11 and<br \/>\nmove 6 steps back or left we get 5.<\/p>\n<p>Question 5.<br \/>\n13 &#8211; 7 = ___6_____<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24663\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-6.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 6\" width=\"423\" height=\"39\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-6.png 423w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-6-300x28.png 300w\" sizes=\"(max-width: 423px) 100vw, 423px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-29972 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-5-1.bmp\" alt=\"\" width=\"445\" height=\"175\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-5-1.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-5-1-300x118.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><br \/>\n13 &#8211; 7 = 6<\/p>\n<p>Explanation:<br \/>\nWe subtract 13 &#8211; 7 = 6, on the number line we start at 13 and<br \/>\nmove 7 steps back or left we get 6.<\/p>\n<p>Question 6.<br \/>\n18 &#8211; 9 = ___9_____<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24663\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-6.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 6\" width=\"423\" height=\"39\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-6.png 423w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-6-300x28.png 300w\" sizes=\"(max-width: 423px) 100vw, 423px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-29973 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-6.bmp\" alt=\"\" width=\"445\" height=\"175\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-6.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-6-300x118.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><br \/>\n18- 9 = 9<\/p>\n<p>Explanation:<br \/>\nWe subtract 18 &#8211; 9 = 9, on number line we start at 18 and<br \/>\nmove 9 steps back or left we get 9.<\/p>\n<p>Question 7.<br \/>\n20 &#8211; 10 = ____10_____<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24663\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-6.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 6\" width=\"423\" height=\"39\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-6.png 423w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-6-300x28.png 300w\" sizes=\"(max-width: 423px) 100vw, 423px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-29974 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-7.bmp\" alt=\"\" width=\"445\" height=\"150\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-7.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-7-300x101.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><br \/>\n20 &#8211; 10 = 10<\/p>\n<p>Explanation:<br \/>\nWe subtract 20 &#8211; 10 = 10, on the number line we start at 20 and<br \/>\nmove 10 steps back or left we get 10.<\/p>\n<p>Question 8.<br \/>\n17 &#8211; 8 = ____9_____<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24663\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-6.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 6\" width=\"423\" height=\"39\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-6.png 423w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-6-300x28.png 300w\" sizes=\"(max-width: 423px) 100vw, 423px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-29976 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-8.bmp\" alt=\"\" width=\"445\" height=\"171\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-8.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-8-300x115.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><br \/>\n17- 8 = 9<\/p>\n<p>Explanation:<br \/>\nWe subtract 17 &#8211; 8 = 9, on the number line we start at 17 and<br \/>\nmove 8 steps back or left we get 9.<\/p>\n<p>Question 9.<br \/>\n18 &#8211; 3 = ____15______<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24663\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-6.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 6\" width=\"423\" height=\"39\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-6.png 423w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-6-300x28.png 300w\" sizes=\"(max-width: 423px) 100vw, 423px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-29977 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-9.bmp\" alt=\"\" width=\"445\" height=\"171\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-9.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-9-300x115.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><\/p>\n<p>18 &#8211; 3 = 15<\/p>\n<p>Explanation:<br \/>\nWe subtract 18 &#8211; 3 = 15, on the number line we start at 18 and<br \/>\nmove 3 steps back or left we get 15.<\/p>\n<p>Question 10.<br \/>\n___12____ = 16 &#8211; 4<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24663\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-6.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 6\" width=\"423\" height=\"39\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-6.png 423w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-6-300x28.png 300w\" sizes=\"(max-width: 423px) 100vw, 423px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-29978 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-10.bmp\" alt=\"\" width=\"445\" height=\"171\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-10.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-10-300x115.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><br \/>\n16- 4 = 12<\/p>\n<p>Explanation:<br \/>\nWe subtract 16 &#8211; 4 = 12, on the number line we start at 16 and<br \/>\nmove 4 steps back or left we get 12.<\/p>\n<p>Question 11.<br \/>\n___6_____ = 14 &#8211; 8<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24663\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-6.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 6\" width=\"423\" height=\"39\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-6.png 423w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-6-300x28.png 300w\" sizes=\"(max-width: 423px) 100vw, 423px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-29979 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-11.bmp\" alt=\"\" width=\"445\" height=\"171\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-11.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-11-300x115.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><br \/>\n14- 8 = 6<\/p>\n<p>Explanation:<br \/>\nWe subtract 14 &#8211; 8 = 6, on the number line we start at 14 and<br \/>\nmove 8 steps back or left we get 6.<\/p>\n<p>Question 12.<br \/>\n<strong>DIG DEEPER!<\/strong><br \/>\nWrite the equation shown by the number line.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24662\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-7.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 7\" width=\"426\" height=\"54\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-7.png 426w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-7-300x38.png 300w\" sizes=\"(max-width: 426px) 100vw, 426px\" \/><br \/>\n___15_____ &#8211; __9______ = ___6_____<br \/>\nAnswer:<br \/>\nThe equation on the number line is 15 &#8211; 9 = 6.<\/p>\n<p>Explanation:<br \/>\nAs shown on the number line we start at 15 and move<br \/>\n9 steps or 9 units back or left we reached at 6 so the equation shown by the number line is 15 &#8211; 9 = 6.<\/p>\n<p><strong>Think and Grow: Modeling Real Life<\/strong><\/p>\n<p>You collect 6 gems. Your friend collects 14. How many fewer gems do you collect?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24661\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-8.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 8\" width=\"132\" height=\"101\" \/><br \/>\nModel:<\/p>\n<p><img loading=\"lazy\" class=\"alignnone size-full wp-image-24660\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-9.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 9\" width=\"427\" height=\"40\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-9.png 427w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-9-300x28.png 300w\" sizes=\"(max-width: 427px) 100vw, 427px\" \/><br \/>\nSubtraction equation:<\/p>\n<p>____8____ fewer gems<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-29981 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-12.bmp\" alt=\"\" width=\"445\" height=\"171\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-12.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-12-300x115.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><br \/>\nSubtraction equation is 14 &#8211; 6 = 8,<br \/>\nI have 8 fewer gems.<\/p>\n<p>Explanation:<br \/>\nGiven I have collected 6 gems and friend collects 14 gems<br \/>\nnow how many less or fewer gems I have than my friend are<br \/>\n14 &#8211; 6 = 8 gems, On number line we start at 14 and<br \/>\nmove 6 steps or 6 units back or left we reach at 8.<br \/>\nSo the Subtraction equation is 14 &#8211; 6 = 8,<br \/>\nI have 8 fewer gems.<\/p>\n<p><strong>Show and Grow<\/strong><\/p>\n<p>Question 13.<br \/>\nYour friend finds 16 gold bars. You find 9. How many fewer gold bars do you find?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24659\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-10.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 10\" width=\"99\" height=\"103\" \/><br \/>\nModel:<\/p>\n<p><img loading=\"lazy\" class=\"alignnone size-full wp-image-24658\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-11.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 11\" width=\"421\" height=\"41\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-11.png 421w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-11-300x29.png 300w\" sizes=\"(max-width: 421px) 100vw, 421px\" \/><br \/>\nSubtraction equation:<\/p>\n<p>_____7_____ gold bars<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-29983 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-13.bmp\" alt=\"\" width=\"445\" height=\"171\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-13.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-13-300x115.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><br \/>\nSubtraction equation is 16 &#8211; 9 = 7,<br \/>\nI have 7 fewer gold bars.<\/p>\n<p>Explanation:<br \/>\nGiven friend finds 16 gold bars and I found 9,<br \/>\nnow how many less or fewer gold bars I have than my friend are<br \/>\n16 &#8211; 9 = 7 gold bars, On number line we start at 16 and<br \/>\nmove 9 steps or 9 units back or left we reach at 7.<br \/>\nSo the Subtraction equation is 16 &#8211; 9 = 7,<br \/>\nI have 7 fewer gold bars.<\/p>\n<h3><a id=\"Count_Back_to_Subtract_within_20_Practice_5.1\"><\/a>Count Back to Subtract within 20 Practice 5.1<\/h3>\n<p>Question 1.<br \/>\n12 &#8211; 5 = __7____<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24657\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-12.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 12\" width=\"423\" height=\"41\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-12.png 423w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-12-300x29.png 300w\" sizes=\"(max-width: 423px) 100vw, 423px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-29986 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-14.bmp\" alt=\"\" width=\"445\" height=\"171\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-14.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-14-300x115.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><br \/>\n12 &#8211; 5 = 7<\/p>\n<p>Explanation:<br \/>\nWe subtract 12 &#8211; 5 = 7, on number line we start at 12 and<br \/>\nmove 5 steps back or left we get 7.<\/p>\n<p>Question 2.<br \/>\n15 &#8211; 7 = ____8____<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24657\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-12.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 12\" width=\"423\" height=\"41\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-12.png 423w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-12-300x29.png 300w\" sizes=\"(max-width: 423px) 100vw, 423px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-29988 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-15.bmp\" alt=\"\" width=\"445\" height=\"171\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-15.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-15-300x115.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><br \/>\n15 &#8211; 7 = 8<\/p>\n<p>Explanation:<br \/>\nWe subtract 15 &#8211; 7 = 8, on number line we start at 15 and<br \/>\nmove 7 steps back or left we get 8.<\/p>\n<p>Question 3.<br \/>\n13 &#8211; 6 = ___7_____<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24657\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-12.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 12\" width=\"423\" height=\"41\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-12.png 423w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-12-300x29.png 300w\" sizes=\"(max-width: 423px) 100vw, 423px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-29989 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-16.bmp\" alt=\"\" width=\"445\" height=\"171\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-16.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-16-300x115.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><br \/>\n13 &#8211; 6 = 7<\/p>\n<p>Explanation:<br \/>\nWe subtract 13 &#8211; 6 = 7, on number line we start at 13 and<br \/>\nmove 6 steps back or left we get 7.<\/p>\n<p>Question 4.<br \/>\n14 &#8211; 5 = ___9_______<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24657\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-12.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 12\" width=\"423\" height=\"41\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-12.png 423w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-12-300x29.png 300w\" sizes=\"(max-width: 423px) 100vw, 423px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-30001 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-17.bmp\" alt=\"\" width=\"445\" height=\"171\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-17.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-17-300x115.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><br \/>\n14 &#8211; 5 = 9<\/p>\n<p>Explanation:<br \/>\nWe subtract 14 &#8211; 5 = 9, on number line we start at 14 and<br \/>\nmove 5 steps back or left we get 9.<\/p>\n<p>Question 5.<br \/>\n11 &#8211; 5 = ____6______<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24657\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-12.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 12\" width=\"423\" height=\"41\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-12.png 423w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-12-300x29.png 300w\" sizes=\"(max-width: 423px) 100vw, 423px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-30004 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-18.bmp\" alt=\"\" width=\"445\" height=\"171\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-18.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-18-300x115.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><br \/>\n11- 5 = 6<\/p>\n<p>Explanation:<br \/>\nWe subtract 11 &#8211; 5 = 6, on number line we start at 11 and<br \/>\nmove 5 steps back or left we get 6.<\/p>\n<p>Question 6.<br \/>\n15 &#8211; 4 = ___11_____<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24657\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-12.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 12\" width=\"423\" height=\"41\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-12.png 423w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-12-300x29.png 300w\" sizes=\"(max-width: 423px) 100vw, 423px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-30007 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-19.bmp\" alt=\"\" width=\"445\" height=\"171\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-19.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-19-300x115.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><br \/>\n15- 4 = 11<\/p>\n<p>Explanation:<br \/>\nWe subtract 15 &#8211; 4 = 11, on number line we start at 15 and<br \/>\nmove 4 steps back or left we get 11.<\/p>\n<p>Question 7.<br \/>\n__10____ = 18 &#8211; 8<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24657\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-12.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 12\" width=\"423\" height=\"41\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-12.png 423w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-12-300x29.png 300w\" sizes=\"(max-width: 423px) 100vw, 423px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-30008 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-20.bmp\" alt=\"\" width=\"445\" height=\"171\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-20.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-20-300x115.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><br \/>\n18 &#8211; 8 = 10<\/p>\n<p>Explanation:<br \/>\nWe subtract 18 &#8211; 8 = 10, on number line we start at 18 and<br \/>\nmove 8 steps back or left we get 10.<\/p>\n<p>Question 8.<br \/>\n____4_____ = 12 &#8211; 8<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24657\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-12.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 12\" width=\"423\" height=\"41\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-12.png 423w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-12-300x29.png 300w\" sizes=\"(max-width: 423px) 100vw, 423px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-30009 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-21.bmp\" alt=\"\" width=\"445\" height=\"171\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-21.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-21-300x115.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><br \/>\n12 &#8211; 8 = 4<\/p>\n<p>Explanation:<br \/>\nWe subtract 12 &#8211; 8 = 4, on number line we start at 12 and<br \/>\nmove 8 steps back or left we get 4.<\/p>\n<p>Question 9.<br \/>\n<strong>DIG DEEPER<\/strong><br \/>\nWrite the equation shown by the number line.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24656\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-13.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 13\" width=\"423\" height=\"55\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-13.png 423w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-13-300x39.png 300w\" sizes=\"(max-width: 423px) 100vw, 423px\" \/><br \/>\n___14_____ &#8211; ___9_____ = ___5_____<br \/>\nAnswer:<\/p>\n<p>The equation on the number line is 14 &#8211; 9 = 5.<\/p>\n<p>Explanation:<br \/>\nAs shown on the number line we start at 14 and move<br \/>\n9 steps or 9 units back or left we reach at 5, so the<br \/>\nequation shown by the number line is 14 &#8211; 9 = 5.<\/p>\n<p>Question 10.<br \/>\n<strong>Modeling Real Life<\/strong><br \/>\nYou play soccer. The visiting team scores 12 goals. Your team scores 4 fewer. How many goals does your team score?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24655\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-14.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 14\" width=\"91\" height=\"76\" \/><\/p>\n<p><img loading=\"lazy\" class=\"alignnone size-full wp-image-24654\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-15.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 15\" width=\"421\" height=\"41\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-15.png 421w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-15-300x29.png 300w\" sizes=\"(max-width: 421px) 100vw, 421px\" \/><\/p>\n<p>_____8_____ goals<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-30011 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-22.bmp\" alt=\"\" width=\"445\" height=\"175\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-22.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-22-300x118.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><\/p>\n<p>Subtraction equation is 12 &#8211; 4 = 8,<br \/>\nMy team scored 8 goals<\/p>\n<p>Explanation:<br \/>\nGiven visiting team scores 12 goals, My team scores 4 fewer goals<br \/>\nMy team have scored 12 &#8211; 4 = 8 goals, On number line we start at<br \/>\n12 and move 4 steps or 4 units back or left we reach at 8.<br \/>\nSo the Subtraction equation is 12 &#8211; 4 = 8,<br \/>\ntherefore my team score 8 goals.<\/p>\n<p><strong>Review &amp; Refresh<\/strong><\/p>\n<p>Question 11.<br \/>\n6 + 2 = ___8_____<br \/>\nAnswer:<br \/>\n6 + 2 = 8<\/p>\n<p>Explanation :<br \/>\nThe addition equation is 6 + 2 = 8,<br \/>\nWe add 2 to 6 we get 8.<\/p>\n<p>Question 12.<br \/>\n4 + 3 = ___7_____<br \/>\nAnswer:<br \/>\n4 + 3 = 7<\/p>\n<p>Explanation :<br \/>\nThe addition equation is 4 + 3 = 7,<br \/>\nWe add 3 to 4 we get 7.<\/p>\n<p>Question 13.<br \/>\n8 + 2 = ___10____<br \/>\nAnswer:<br \/>\n8 + 2 = 10<\/p>\n<p>Explanation :<br \/>\nThe addition equation is 8 + 2 = 10,<br \/>\nWe add 2 to 8 we get 10.<\/p>\n<p>Question 14.<br \/>\n5 + 4 = ____9___<br \/>\nAnswer:<br \/>\n5 + 4 = 9<\/p>\n<p>Explanation :<br \/>\nThe addition equation is 5 + 4 = 9,<br \/>\nWe add 4 to 5 we get 9.<\/p>\n<h3><a id=\"Lesson_5.2_Use_Addition_to_Subtract_within_20\"><\/a>Lesson 5.2 Use Addition to Subtract within 20<\/h3>\n<p><strong>Explore and Grow<\/strong><\/p>\n<p>Model the story.<br \/>\nYour class needs to make 15 scrapbook pages. 8 are already made. How many more pages does your class need to make?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24687\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-16.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 5 Subtract Numbers within 20 16\" width=\"117\" height=\"77\" \/><\/p>\n<p><img loading=\"lazy\" class=\"alignnone size-full wp-image-24686\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-17.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 5 Subtract Numbers within 20 17\" width=\"423\" height=\"41\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-17.png 423w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-17-300x29.png 300w\" sizes=\"(max-width: 423px) 100vw, 423px\" \/><\/p>\n<p>____7_____ more pages<br \/>\n<img loading=\"lazy\" class=\"alignnone\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-3.bmp\" alt=\"\" width=\"445\" height=\"175\" \/><br \/>\n15 &#8211; 8 = 7,<br \/>\nWe need 7 more pages to make.<\/p>\n<p>Explanation:<br \/>\nGiven my class needs to make 15 scrapbook pages,<br \/>\n8 are already made ,We need 15 &#8211; 8 = 7 more pages<br \/>\nare needed\u00a0 to make scrapbook.<\/p>\n<p><strong>Show and Grow<\/strong><\/p>\n<p>Question 1.<br \/>\n11 &#8211; 7 = ?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24685\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-18.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 5 Subtract Numbers within 20 18\" width=\"422\" height=\"39\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-18.png 422w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-18-300x28.png 300w\" sizes=\"(max-width: 422px) 100vw, 422px\" \/><br \/>\nThink 7 + ___4____ = 11.<br \/>\nSo, 11 &#8211; 7 = ___4____ .<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-30013 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-23-1.bmp\" alt=\"\" width=\"468\" height=\"267\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-23-1.bmp 468w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-23-1-300x171.jpg 300w\" sizes=\"(max-width: 468px) 100vw, 468px\" \/><br \/>\n7 + 4 = 11<br \/>\n11 &#8211; 7 = 4<\/p>\n<p>Explanation:<br \/>\nExplanation:<br \/>\nFirst we move from 7 on number line and start moving till<br \/>\n11 we count how many units right we have moved we get<br \/>\n4 units so 7 + 4 = 11 or we start at 11 on number line and<br \/>\nmove 7 steps back or left we get 4, 11 &#8211; 7 = 4.<\/p>\n<p>Question 2.<br \/>\n16 &#8211; 8 = ?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24684\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-19.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 5 Subtract Numbers within 20 19\" width=\"421\" height=\"42\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-19.png 421w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-19-300x30.png 300w\" sizes=\"(max-width: 421px) 100vw, 421px\" \/><br \/>\nThink 8 + ___8____ = 16.<br \/>\nSo, 16 &#8211; 8 = ___8____ .<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-30015 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-24.bmp\" alt=\"\" width=\"468\" height=\"267\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-24.bmp 468w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-24-300x171.jpg 300w\" sizes=\"(max-width: 468px) 100vw, 468px\" \/><\/p>\n<p>8 + 8 = 16<br \/>\n16 &#8211; 8 = 8<\/p>\n<p>Explanation:<br \/>\nFirst we move from 8 on number line and start moving till<br \/>\n16 we count how many units right we have moved we get<br \/>\n8 units so 8 + 8 = 16 or we start at 16 on number line and<br \/>\nmove 8 steps back or left we get 8, 16 &#8211; 8 = 8.<\/p>\n<p>Question 3.<br \/>\n13 &#8211; 10 = ?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24684\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-19.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 5 Subtract Numbers within 20 19\" width=\"421\" height=\"42\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-19.png 421w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-19-300x30.png 300w\" sizes=\"(max-width: 421px) 100vw, 421px\" \/><br \/>\nThink 10 + __3_____ = 13.<br \/>\nSo, 13 &#8211; 10 = ___3____ .<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-30016 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-25.bmp\" alt=\"\" width=\"468\" height=\"267\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-25.bmp 468w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-25-300x171.jpg 300w\" sizes=\"(max-width: 468px) 100vw, 468px\" \/><br \/>\n10 + 3 = 13<br \/>\n13 &#8211; 10 = 3<\/p>\n<p>Explanation:<br \/>\nFirst we move from 10 on number line and start moving till<br \/>\n13 we count how many units right we have moved we get<br \/>\n3 units so 10 + 3 = 13 or we start at 13 on number line and<br \/>\nmove 10 steps back or left we get 3, 13 &#8211; 10 = 3.<\/p>\n<p><strong>Apply and Grow: Practice<\/strong><\/p>\n<p>Question 4.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24684\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-19.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 5 Subtract Numbers within 20 19\" width=\"421\" height=\"42\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-19.png 421w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-19-300x30.png 300w\" sizes=\"(max-width: 421px) 100vw, 421px\" \/><br \/>\n12 &#8211; 7 = ?<br \/>\nThink 7 + ___5____ = 12.<br \/>\nSo, 12 &#8211; 7 = ___5____ .<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-30017 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-26.bmp\" alt=\"\" width=\"468\" height=\"267\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-26.bmp 468w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-26-300x171.jpg 300w\" sizes=\"(max-width: 468px) 100vw, 468px\" \/><\/p>\n<p>7 + 5 = 12<br \/>\n12 &#8211; 7 = 5<\/p>\n<p>Explanation:<br \/>\nFirst we move from 7 on number line and start moving till<br \/>\n12 we count how many units right we have moved we get<br \/>\n5 units so 7 + 5 = 12 or we start at 12 on number line and<br \/>\nmove 7 steps back or left we get 5, 12 &#8211; 7 = 5.<\/p>\n<p>Question 5.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24684\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-19.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 5 Subtract Numbers within 20 19\" width=\"421\" height=\"42\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-19.png 421w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-19-300x30.png 300w\" sizes=\"(max-width: 421px) 100vw, 421px\" \/><br \/>\n17 &#8211; 8 = ?<br \/>\nThink 8 + ___9____ = 17.<br \/>\nSo, 17 &#8211; 8 = __9____ .<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-30036 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-26-1.bmp\" alt=\"\" width=\"468\" height=\"267\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-26-1.bmp 468w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-26-1-300x171.jpg 300w\" sizes=\"(max-width: 468px) 100vw, 468px\" \/><\/p>\n<p>8 + 9 = 17<br \/>\n17 &#8211; 8 = 9<\/p>\n<p>Explanation:<br \/>\nFirst we move from 8 on number line and start moving till<br \/>\n17 we count how many units right we have moved we get<br \/>\n9 units so 8 + 9 = 17 or we start at 17 on number line and<br \/>\nmove 8 steps back or left we get 9, 17 &#8211; 8 = 9.<\/p>\n<p>Question 6.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24684\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-19.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 5 Subtract Numbers within 20 19\" width=\"421\" height=\"42\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-19.png 421w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-19-300x30.png 300w\" sizes=\"(max-width: 421px) 100vw, 421px\" \/><br \/>\n11 &#8211; 2 = ___9_____<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-30039 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-27.bmp\" alt=\"\" width=\"445\" height=\"171\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-27.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-27-300x115.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><br \/>\n11 &#8211; 2 = 9<\/p>\n<p>Explanation:<br \/>\nWe subtract 11 &#8211; 2 = 9, on number line we start at 11 and<br \/>\nmove 2 steps back or left we get 9.<\/p>\n<p>Question 7.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24684\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-19.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 5 Subtract Numbers within 20 19\" width=\"421\" height=\"42\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-19.png 421w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-19-300x30.png 300w\" sizes=\"(max-width: 421px) 100vw, 421px\" \/><br \/>\n_____14____ = 19 &#8211; 5<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-30041 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-28.bmp\" alt=\"\" width=\"445\" height=\"171\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-28.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-28-300x115.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><br \/>\n19 &#8211; 5 = 14 or 14 = 19 &#8211; 5<\/p>\n<p>Explanation:<br \/>\nWe subtract 19 &#8211; 5 = 14, on number line we start at 19 and<br \/>\nmove 5 steps back or left we get 14.<\/p>\n<p>Question 8.<br \/>\n<strong>DIG DEEPER!<\/strong><br \/>\nTell what subtraction problem Newton and Descartes solved. Think: What strategies did they use?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24683\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-20.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 5 Subtract Numbers within 20 20\" width=\"459\" height=\"219\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-20.png 459w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-20-300x143.png 300w\" sizes=\"(max-width: 459px) 100vw, 459px\" \/><br \/>\nAnswer:<br \/>\nNewton and Descartes solved the subtraction equation as<br \/>\nFirst\u00a0 by 5 + <span style=\"text-decoration: underline;\">8\u00a0<\/span> = 13<br \/>\nSecond by 13 &#8211; 5 =_<span style=\"text-decoration: underline;\">8\u00a0<\/span><\/p>\n<p>Explanation :<br \/>\nNewton and Descartes solved the subtraction equation on the number line<br \/>\nfirst they solved equation 5 + _______ = 13 as started from 5 and moved<br \/>\n8 units right reached till 13 so the missing number is 8, 5 + 8 = 13.<br \/>\nIn second method they solved by starting from 13 and moved 5 units<br \/>\nleft till they reached 8 on the number line so they solved<br \/>\nthe subtraction equation as 13 &#8211; 5 = 8.<\/p>\n<p><strong>Think and Grow: Modeling Real Life<\/strong><\/p>\n<p>There are 15 people in an elevator. Some of them exit. There are 7 left. How many people exit?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24682\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-21.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 5 Subtract Numbers within 20 21\" width=\"150\" height=\"136\" \/><br \/>\nModel:<\/p>\n<p><img loading=\"lazy\" class=\"alignnone size-full wp-image-24681\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-22.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 5 Subtract Numbers within 20 22\" width=\"423\" height=\"38\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-22.png 423w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-22-300x27.png 300w\" sizes=\"(max-width: 423px) 100vw, 423px\" \/><br \/>\nSubtraction equation:<br \/>\n15 &#8211; 7 = 8<\/p>\n<p>____8_____ people<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-30044 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-29.bmp\" alt=\"\" width=\"445\" height=\"171\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-29.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-29-300x115.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><\/p>\n<p>15 &#8211; 7 = 8,<br \/>\n8 people exit.<\/p>\n<p>Explanation:<br \/>\nGiven 15 people are there in elevator, some of them exit,<br \/>\nThere are 7 left, So people exit are 15 &#8211; 7 = 8,<br \/>\nSo 8 people exit from elevator.<\/p>\n<p><strong>Show and Grow<\/strong><\/p>\n<p>Question 9.<br \/>\nThere are 18 people in a subway car. Some of them exit. There are 9 left. How many people exit?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24680\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-23.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 5 Subtract Numbers within 20 23\" width=\"184\" height=\"132\" \/><br \/>\nModel:<\/p>\n<p><img loading=\"lazy\" class=\"alignnone size-full wp-image-24681\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-22.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 5 Subtract Numbers within 20 22\" width=\"423\" height=\"38\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-22.png 423w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-22-300x27.png 300w\" sizes=\"(max-width: 423px) 100vw, 423px\" \/><br \/>\nSubtraction equation:<br \/>\n18 -9 = 9<\/p>\n<p>_____9_____ people<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-30045 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-30.bmp\" alt=\"\" width=\"445\" height=\"175\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-30.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-30-300x118.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><\/p>\n<p>18 &#8211; 9 = 9,<br \/>\n9 people exit.<\/p>\n<p>Explanation:<br \/>\nGiven there are 18 people in a subway car , some of them exit,<br \/>\nThere are 9 left, So people exit are 18 &#8211; 9 = 9,<br \/>\nSo 9 people exit from subway car.<\/p>\n<h3><a id=\"Use_Addition_to_Subtract_within_20_Practice_5.2\"><\/a>Use Addition to Subtract within 20 Practice 5.2<\/h3>\n<p>Question 1.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24679\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-24.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 5 Subtract Numbers within 20 24\" width=\"424\" height=\"43\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-24.png 424w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-24-300x30.png 300w\" sizes=\"(max-width: 424px) 100vw, 424px\" \/><br \/>\n13 &#8211; 9 = ?<br \/>\nThink 9 + __4____ = 13<br \/>\nSo, 13 &#8211; 9 = ___4____.<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-30266 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-31.bmp\" alt=\"\" width=\"468\" height=\"267\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-31.bmp 468w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-31-300x171.jpg 300w\" sizes=\"(max-width: 468px) 100vw, 468px\" \/><\/p>\n<p>9 + 4 = 13<br \/>\n13 &#8211; 9 = 4<\/p>\n<p>Explanation:<br \/>\nFirst we move from 9 on number line and start moving till<br \/>\n13 we count how many units right we have moved we get<br \/>\n4 units so 9 + 4 = 13 or we start at 13 on number line and<br \/>\nmove 9 steps back or left we get 4, 13 &#8211; 9 = 4.<\/p>\n<p>Question 2.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24679\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-24.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 5 Subtract Numbers within 20 24\" width=\"424\" height=\"43\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-24.png 424w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-24-300x30.png 300w\" sizes=\"(max-width: 424px) 100vw, 424px\" \/><br \/>\n17 &#8211; 8 = ?<br \/>\nThink 8 + __9____ = 17<br \/>\nSo, 17 &#8211; 8 = ___9____.<br \/>\nAnswer:<\/p>\n<p>8 + 9 = 17<br \/>\n17 &#8211; 8 = 9<\/p>\n<p>Explanation:<br \/>\nFirst we move from 8 on number line and start moving till<br \/>\n17 we count how many units right we have moved we get<br \/>\n9 units so 8 + 9 = 17 or we start at 17 on number line and<br \/>\nmove 8 steps back or left we get 9, 17 &#8211; 8 = 9.<\/p>\n<p>Question 3.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24679\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-24.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 5 Subtract Numbers within 20 24\" width=\"424\" height=\"43\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-24.png 424w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-24-300x30.png 300w\" sizes=\"(max-width: 424px) 100vw, 424px\" \/><br \/>\n14 &#8211; 7 = ____7_____<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-30267 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-32.bmp\" alt=\"\" width=\"445\" height=\"171\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-32.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-32-300x115.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><\/p>\n<p>14 &#8211; 7 = 7<\/p>\n<p>Explanation:<br \/>\nWe subtract 14 &#8211; 7 = 7, on number line we start at 14 and<br \/>\nmove 7 steps back or left we get 7.<\/p>\n<p>Question 4.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24679\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-24.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 5 Subtract Numbers within 20 24\" width=\"424\" height=\"43\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-24.png 424w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-24-300x30.png 300w\" sizes=\"(max-width: 424px) 100vw, 424px\" \/><br \/>\n____13_____ = 17 &#8211; 4<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-30269 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-33.bmp\" alt=\"\" width=\"481\" height=\"127\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-33.bmp 481w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Subtract-33-300x79.jpg 300w\" sizes=\"(max-width: 481px) 100vw, 481px\" \/><\/p>\n<p>17 &#8211; 4 = 13<\/p>\n<p>Explanation:<br \/>\nWe subtract 17 &#8211; 4 = 13, on number line we start at 17 and<br \/>\nmove 4 steps back or left we get 13.<\/p>\n<p>Question 5.<br \/>\n<strong>DIG DEEPER!<\/strong><br \/>\nTell what subtraction problem Newton and Descartes solved. Think: What strategies did they use?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24678\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-25.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 5 Subtract Numbers within 20 25\" width=\"456\" height=\"196\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-25.png 456w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-25-300x129.png 300w\" sizes=\"(max-width: 456px) 100vw, 456px\" \/><br \/>\nAnswer:<br \/>\nNewton and Descartes solved the subtraction equation as<br \/>\nFirst by 11 &#8211; 7 =<span style=\"text-decoration: underline;\">_4\u00a0<\/span><br \/>\nSecond\u00a0 by 7 + <span style=\"text-decoration: underline;\">\u00a04\u00a0<\/span> =\u00a0 11<\/p>\n<p>Explanation :<br \/>\nNewton and Descartes solved the subtraction equation on the number line<br \/>\nfirst method they solved by starting from 11 and moved 7 units<br \/>\nleft till they reached 4 on the number line so they solved<br \/>\nthe subtraction equation as 11 &#8211; 7 = 4.<br \/>\nSecond they solved equation 7 + ______ = 11 as started from 7 and moved<br \/>\n4 units right reached till 11 so the missing number is 4, 7 + 4 = 11.<\/p>\n<p>Question 6.<br \/>\n<strong>Modeling Real Life<\/strong><br \/>\nThere are 13 people on a train. Some of them exit. There are 6 left. How many people exit?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24677\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-26.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 5 Subtract Numbers within 20 26\" width=\"183\" height=\"132\" \/><\/p>\n<p><img loading=\"lazy\" class=\"alignnone size-full wp-image-24676\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-27.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 5 Subtract Numbers within 20 27\" width=\"425\" height=\"44\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-27.png 425w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-27-300x31.png 300w\" sizes=\"(max-width: 425px) 100vw, 425px\" \/><\/p>\n<p>_____7_______ people<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-30868\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-1.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-1\" width=\"578\" height=\"123\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-1.bmp 578w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-1-300x64.jpg 300w\" sizes=\"(max-width: 578px) 100vw, 578px\" \/><\/p>\n<p>13 &#8211; 6 = 7,<br \/>\nSo, 7 people exit.<\/p>\n<p>Explanation:<br \/>\nGiven there are 13 people on a train , some of them exit,<br \/>\nThere are 7 left, So people exit are 13 &#8211; 6 = 7,<br \/>\nSo 7 people exit from the train.<\/p>\n<p><strong>Review &amp; Refresh<\/strong><\/p>\n<p>Question 7.<br \/>\n10 &#8211; 9 = ____1______<br \/>\nAnswer:<br \/>\n10 &#8211; 9 = 1<\/p>\n<p>Explanation :<br \/>\nThe subtraction equation is 10 &#8211; 9 = 1,<br \/>\nWe subtract 9 from 10 we get 1.<\/p>\n<p>Question 8.<br \/>\n9 &#8211; 9 = ____0______<br \/>\nAnswer:<br \/>\n9 &#8211; 9 = 0<\/p>\n<p>Explanation :<br \/>\nThe subtraction equation is 9 &#8211; 9 = 0,<br \/>\nWe subtract\u00a0 9 from 9 we get 0.<\/p>\n<h3><a id=\"Lesson_5.3_Subtract_9\"><\/a>Lesson 5.3 Subtract 9<\/h3>\n<p><strong>Explore and Grow<\/strong><\/p>\n<p>Use counters to find each difference.<\/p>\n<p><img loading=\"lazy\" class=\"alignnone size-full wp-image-24705\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-28.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20 28\" width=\"380\" height=\"404\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-28.png 380w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-28-282x300.png 282w\" sizes=\"(max-width: 380px) 100vw, 380px\" \/><\/p>\n<p><img loading=\"lazy\" class=\"alignnone size-full wp-image-31249\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-2-1.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-2\" width=\"790\" height=\"428\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-2-1.bmp 790w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-2-1-300x163.jpg 300w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-2-1-768x416.jpg 768w\" sizes=\"(max-width: 790px) 100vw, 790px\" \/><br \/>\nExplanation:<br \/>\nTo find 15 -10 =\u00a0 here we use two counters\u00a0 first<br \/>\nwe take total 15 circles in that we strike 10 numbers<br \/>\nthe left number of circles are 5, So 15 &#8211; 10 = 5.<br \/>\nTo find 15 &#8211; 9 = here we use two counters and we take<br \/>\n15 circles in that we will strike out 9 numbers the left are<br \/>\n6, So 15 &#8211; 9 = 6.<\/p>\n<p><strong>Show and Grow<\/strong><\/p>\n<p>Get to 10 to subtract.<\/p>\n<p>Question 1.<br \/>\n17 &#8211; 9 = ?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24704\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-29.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20 29\" width=\"124\" height=\"113\" \/><br \/>\n17 &#8211; __7____ = 10<br \/>\n10 &#8211; ___2____ = ___8___<br \/>\nSo, 17 &#8211; 9 = ___8_____<br \/>\nAnswer:<br \/>\n17 &#8211; 7 = 10 we get 10<br \/>\n10 &#8211; 2 = 8,<br \/>\nSo 17 &#8211; 9 = 8<\/p>\n<p>Explanation:<br \/>\nWe have 2 counters in counter one we have 10 circles<br \/>\nand in next counter we have 7 circles so in total we have 17,<br \/>\nFirst we see out of 17 if we consider counter-2 we have 7 strike outs<br \/>\nmeans 17 &#8211; 7 = 10 we got 10 in counter-1 and if we see first counter<br \/>\nwe have 2 strike outs 10 &#8211; 2 = 8, So total number of circles strike out<br \/>\nfrom 2-counters are 7 + 2 = 9, So making equation as 17 &#8211; 9 = 8.<\/p>\n<p>Question 2.<br \/>\n14- 9 = ?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24703\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-30.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20 30\" width=\"123\" height=\"116\" \/><br \/>\n14 &#8211; __4____ = 10<br \/>\n10 &#8211; ___5____ = ___5___<br \/>\nSo, 14 &#8211; 9 = _____5___<br \/>\nAnswer:<br \/>\n14 &#8211; 4\u00a0 = 10 we get 10<br \/>\n10 &#8211; 5 = 5<br \/>\nSo 14 &#8211; 9 = 5<\/p>\n<p>Explanation:<br \/>\nWe have\u00a0 2 counters in counter one we have 10 circles<br \/>\nand in next counter we have 4 circles so in total we have 14,<br \/>\nFirst we see out of 14 if we consider counter-2 we have 4 strike outs<br \/>\nmeans 14 &#8211; 4 = 10 we got 10 in counter-1 and if we see first counter<br \/>\nwe have 5 strike outs 10 &#8211; 5 = 5,So total number of circles strike out<br \/>\nfrom 2-counters are 4 + 5 = 9, So making equation as 14 &#8211; 9 = 5.<\/p>\n<p><strong>Apply and Grow: Practice<\/strong><\/p>\n<p>Question 3.<br \/>\n16 &#8211; 9 = ?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24702\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-31.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20 31\" width=\"122\" height=\"114\" \/><br \/>\n16 &#8211; ___6___ = 10<br \/>\n10 &#8211; ____3___ = __7____<br \/>\nSo, 16 &#8211; 9 = ___7_____<br \/>\nAnswer:<br \/>\n16 &#8211; 6 = 10 we get 10<br \/>\n10 &#8211; 3 = 7<br \/>\nSo 16 &#8211; 9 = 7<\/p>\n<p>Explanation:<br \/>\nWe have\u00a0 2 counters in counter one we have 10 circles<br \/>\nand in next counter we have 6 circles so in total we have 16,<br \/>\nFirst we see out of 16 if we consider counter-2 we have 6 strike outs<br \/>\nmeans 16 &#8211; 6 = 10 we got 10 in counter-1 and if we see first counter<br \/>\nwe have 3 strike outs 10 &#8211; 3 = 7, So total number of circles strike out<br \/>\nfrom 2-counters are 6 + 3 = 9, So making equation as 16 &#8211; 9 = 7.<\/p>\n<p>Question 4.<br \/>\n11 &#8211; 9 = ?<br \/>\n11 &#8211; ___1____ = 10<br \/>\n10 &#8211; ___8____ = ___2____<br \/>\nS0, 11 &#8211; 9 = ____2____ .<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone wp-image-30901 size-full\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-3.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-3\" width=\"180\" height=\"128\" \/><br \/>\n11 &#8211; 1 = 10 we get 10<br \/>\n10 &#8211; 8 = 2<br \/>\nSo 11 &#8211; 9 = 2<\/p>\n<p>Explanation:<br \/>\nTo solve 11 &#8211; 9\u00a0 and to get 10,<br \/>\nWe solve by using 2 counters in counter one we have 10 circles<br \/>\nand in next counter we have 1 circle so in total we have 11,<br \/>\nNow in all we will strike 9 circles, 1 circle from counter-2 making equation<br \/>\nas 11 &#8211; 1 = 10 we got 10 in counter-1 and we strike out\u00a0 8 circles from counter-1<br \/>\nwe are left with 2 making it as 10 &#8211; 8 = 2, So in total we have taken 8 + 1 = 9<br \/>\nfrom 11 in 2-counters, making equation as 11 -9 = 2 as shown in the picture.<\/p>\n<p>Question 5.<br \/>\n15 &#8211; 9 = ?<br \/>\n15 &#8211; __5_____ = 10<br \/>\n10 &#8211; __4______ = __6______<br \/>\nSo, 15 &#8211; 9 = ___6_____<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-30905\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-4.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-4\" width=\"180\" height=\"128\" \/><br \/>\n15- 5 = 10 we get 10<br \/>\n10 &#8211; 4 = 6<br \/>\nSo 15 &#8211; 9 = 6<\/p>\n<p>Explanation:<br \/>\nTo solve 15 &#8211; 9\u00a0 and to get 10,<br \/>\nWe solve by using 2 counters in counter one we have 10 circles<br \/>\nand in next counter we have 5 circles so in total we have 15,<br \/>\nNow in all we will strike 9 circles, 5 circles from counter-2 making equation<br \/>\nas 15 &#8211; 5 = 10 we got 10 in counter-1 and we strike 4 circles from counter-1<br \/>\nwe are left with 6 making it as 10 &#8211; 4 = 6, So in total we have taken 5 + 4 = 9<br \/>\nfrom 15 in 2-counters, making equation as 15 -9 = 6 as shown in the picture.<\/p>\n<p>Question 6.<br \/>\nMP Structure<br \/>\nWhich models show 12 &#8211; 9?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24701\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-32.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20 32\" width=\"471\" height=\"115\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-32.png 471w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-32-300x73.png 300w\" sizes=\"(max-width: 471px) 100vw, 471px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-30907\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-5.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-5\" width=\"225\" height=\"128\" \/> <img loading=\"lazy\" class=\"alignnone size-full wp-image-30909\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-6.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-6\" width=\"159\" height=\"119\" \/><\/p>\n<p>First model and third model shows 12 &#8211; 9.<\/p>\n<p>Explanation:<br \/>\nIf we see all models are having 12 now we will see which model is subtracting 9,<br \/>\nFor this we consider both counters and count total strike outs<br \/>\nModel 1 have 9 strike outs , Model 2 have 10 strike outs,<br \/>\nModel 3 have 9 strike outs, So first model and third model shows 12 &#8211; 9.<\/p>\n<p><strong>Think and Grow: Modeling Real Life<\/strong><\/p>\n<p>You have 12 eggs. You use 9 of them. How many eggs are left?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24700\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-33.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20 33\" width=\"167\" height=\"125\" \/><br \/>\nModel:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24699\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-34.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20 34\" width=\"127\" height=\"113\" \/><br \/>\nSubtraction equation:<\/p>\n<p>___3_______ eggs<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-30911\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-7.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-7\" width=\"225\" height=\"128\" \/><br \/>\n12 &#8211; 9 = 3,<br \/>\nSo 3 eggs are left.<\/p>\n<p>Explanation:<br \/>\nGiven I have 12 eggs and use 9 eggs,<br \/>\nBy using counters first I take total 12 circles then I strike out 9,<br \/>\nSo left are 3 so the subtraction equation is 12 &#8211; 9 = 3,<br \/>\nSo 3 eggs are left.<\/p>\n<p><strong>Show and Grow<\/strong><\/p>\n<p>Question 7.<br \/>\nAn egg carton has 18 eggs. You crack 9 of them. How many eggs are not cracked?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24698\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-35.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20 35\" width=\"92\" height=\"69\" \/><br \/>\nModel:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24699\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-34.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20 34\" width=\"127\" height=\"113\" \/><br \/>\nSubtraction equation:<\/p>\n<p>_____9_______ eggs<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-30912\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-8.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-8\" width=\"180\" height=\"128\" \/><br \/>\n18 &#8211; 9 = 9,<br \/>\nSo 9 eggs are not cracked.<\/p>\n<p>Explanation:<br \/>\nGiven egg carton has 18 eggs and crack 9 of them,<br \/>\nBy using counters first I take total 18 circles then I strike out 9,<br \/>\nSo left are 9 so the subtraction equation is 18 &#8211; 9 = 9,<br \/>\nSo 9 eggs are not cracked.<\/p>\n<h3><a id=\"Subtract_9_Practice_5.3\"><\/a>Subtract 9 Practice 5.3<\/h3>\n<p>Get to 10 to subtract.<\/p>\n<p>Question 1.<br \/>\n18 &#8211; 9 = ?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24697\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-36.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20 36\" width=\"122\" height=\"111\" \/><br \/>\n18 &#8211; ___8_____ = 10<br \/>\n10 &#8211; __1_____ = __9_____<br \/>\nSo, 18 &#8211; 9 = ____9_____ .<br \/>\nAnswer:<\/p>\n<p>18- 8 = 10 we get 10<br \/>\n10 &#8211; 1 = 9<br \/>\nSo 18 &#8211; 9 = 9<\/p>\n<p>Explanation:<br \/>\nTo solve 18 &#8211; 9\u00a0 and to get 10,<br \/>\nWe solve by using 2 counters in counter one we have 10 circles<br \/>\nand in next counter we have 8 circles so in total we have 18,<br \/>\nNow in all we will strike 9 circles, 8 circles from counter-2 making equation<br \/>\nas 18 &#8211; 8 = 10 we got 10 in counter-1 and we strike 1 circle from counter-1<br \/>\nwe are left with 9 making it as 10 &#8211; 1 = 9, So in total we have taken 8 + 1 = 9<br \/>\nfrom 18 in 2-counters, making equation as 18 &#8211; 9 = 9 as shown in the picture.<\/p>\n<p>Question 2.<br \/>\n12 &#8211; 9 = ?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24696\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-37.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20 37\" width=\"125\" height=\"116\" \/><br \/>\n12 &#8211; ___2_____ = 10<br \/>\n10 &#8211; ___7____ = ___3____<br \/>\nSo, 12 &#8211; 9 = _____3____ .<br \/>\nAnswer:<br \/>\n12 &#8211; 2 = 10 we get 10<br \/>\n10 &#8211; 7 = 3<br \/>\n12 &#8211; 9 = 3<\/p>\n<p>Explanation:<br \/>\nTo solve 12 &#8211; 9\u00a0 and to get 10,<br \/>\nWe solve by using 2 counters in counter one we have 10 circles<br \/>\nand in next counter we have 2 circles so in total we have 12,<br \/>\nNow in all we will strike 9 circles, 2 circles from counter-2 making equation<br \/>\nas 12 &#8211; 2 = 10 we got 10 in counter-1 and we strike 7 circles from counter-1<br \/>\nwe are left with 3 making it as 10 &#8211; 7 = 3, So in total we have taken 2 + 7 = 9<br \/>\nfrom 12 in 2-counters, making equation as 12 &#8211; 9 = 3 as shown in the picture.<\/p>\n<p>Question 3.<br \/>\n19 &#8211; 9 = ?<br \/>\n19 &#8211; ____9____ = 10<br \/>\n10 &#8211; ___0____ = ___10____<br \/>\nSo, 19 &#8211; 9 = ____10_____ .<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-31176\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-9.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-9\" width=\"180\" height=\"128\" \/><br \/>\n19 &#8211; 9 = 10,<br \/>\n10 &#8211; 0 = 10<br \/>\nSo, 19 -9 = 10<\/p>\n<p>Explanation:<br \/>\nTo solve 19 &#8211; 9\u00a0 and to get 10,<br \/>\nWe solve by using 2 counters in counter one we have 10 circles<br \/>\nand in next counter we have 9 circles so in total we have 19,<br \/>\nNow in all we will strike 9 circles, 9 circles from counter-2 making equation<br \/>\nas 19 &#8211; 9 = 10 we got 10 in counter-1, we will not strike in counter-1 as we have<br \/>\nalready taken 9 ,So 10 &#8211; 0 = 10, We are left with 10 and the equation is 19 &#8211; 9 = 10.<\/p>\n<p>Question 4.<br \/>\n<strong>MP Structure<\/strong><br \/>\nWhich models show 16 &#8211; 9?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24695\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-38.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20 38\" width=\"457\" height=\"112\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-38.png 457w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-38-300x74.png 300w\" sizes=\"(max-width: 457px) 100vw, 457px\" \/><br \/>\nAnswer:<\/p>\n<p>Second model and third model shows 16 &#8211; 9.<\/p>\n<p>Explanation:<br \/>\nIf we see all models are having 16 now we will see which model is subtracting 9,<br \/>\nFor this we consider both counters and count total strike outs<br \/>\nModel 1 have 10 strike outs , Model 2 have 9 strike outs,<br \/>\nModel 3 have 9 strike outs, So Second model and third model shows 16 &#8211; 9.<\/p>\n<p>Question 5.<br \/>\n<strong>Modeling Real Life<\/strong><br \/>\nYou have 14 water balloons. You break 9 of them. How many water balloons are left?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24694\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-39.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20 39\" width=\"176\" height=\"129\" \/><br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24693\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-40.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20 40\" width=\"127\" height=\"118\" \/><\/p>\n<p>____5______ Water balloons<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-31192\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-10.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-10\" width=\"180\" height=\"128\" \/><br \/>\n14 &#8211; 9 = 5<br \/>\n5 water balloons are left.<\/p>\n<p>Explanation:<br \/>\nGiven I have 14 water balloons. I break 9 of them,<br \/>\nSo I will take 2 counters counter-1 has 10 circles and counter-2 has<br \/>\n4 circles in all I have 14 number of circles, now over all I will<br \/>\nstrike out 9 from the 2-counters. As counter-2 has only 4 I will take 5 from<br \/>\ncounter-1 so that in total 4 + 5 = 9 circles are strike out so we are left with 5,<br \/>\nSo the subtraction equation is 14\u00a0 &#8211; 9 = 5, So 5 water balloons are left.<\/p>\n<p><strong>Review &amp; Refresh<\/strong><\/p>\n<p>Question 6.<br \/>\nUse the picture to complete the number bond.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24692\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-41.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20 41\" width=\"427\" height=\"171\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-41.png 427w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-41-300x120.png 300w\" sizes=\"(max-width: 427px) 100vw, 427px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-31225\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-11-1.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-11\" width=\"427\" height=\"171\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-11-1.bmp 427w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-11-1-300x120.jpg 300w\" sizes=\"(max-width: 427px) 100vw, 427px\" \/><\/p>\n<p>Explanation:<br \/>\nNumber bonds are pictures that show the bond between parts and whole.<br \/>\nSo here we know that 10 is the whole number<br \/>\nand 8 is one of the numbers from the pair of number bonds.<br \/>\nThe other number that combines with 8 to give 10 is 2.<\/p>\n<h3><a id=\"Lesson_5.4_Get_to_10_to_Subtract\"><\/a>Lesson 5.4 Get to 10 to Subtract<\/h3>\n<p><strong>Explore and Grow<\/strong><\/p>\n<p>Use counters to find the difference. Show how you can make a 10 to solve.<\/p>\n<p><img loading=\"lazy\" class=\"alignnone size-full wp-image-24726\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-42.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 42\" width=\"380\" height=\"408\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-42.png 380w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-42-279x300.png 279w\" sizes=\"(max-width: 380px) 100vw, 380px\" \/><br \/>\nAnswer:<\/p>\n<p><img loading=\"lazy\" class=\"alignnone size-full wp-image-31260\" style=\"font-weight: inherit;\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-12.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-12\" width=\"180\" height=\"128\" \/><\/p>\n<p>14 &#8211; <span style=\"font-size: 16px;\">4 = 10<br \/>\n<\/span>10 &#8211; 2 = 8<br \/>\n14 &#8211; 6 = 8<\/p>\n<p>Explanation:<br \/>\nTo solve 14 &#8211; 6\u00a0 and to get 10,<br \/>\nWe solve by using 2 counters in counter one we have 10 circles<br \/>\nand in next counter we have 4 circles so in total we have 14,<br \/>\nNow in all we will strike 6 circles, 4 circles from counter-2 making equation<br \/>\nas 14 &#8211; 4 = 10 we got 10 in counter-1 and we strike 2 circles from counter-1<br \/>\nwe are left with 8 making it as 10 &#8211; 2 = 8, So in total we have taken 4 + 2 = 6<br \/>\nfrom 14 in 2-counters, making equation as 14 &#8211; 6 = 8 as shown in the picture.<\/p>\n<p><strong>Show and Grow<\/strong><\/p>\n<p>Get to 10 to subtract.<\/p>\n<p>Question 1.<br \/>\n12 &#8211; 5 = ?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24725\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-43.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 43\" width=\"125\" height=\"113\" \/><br \/>\n12 &#8211; __2____ = 10<br \/>\n10 &#8211; __3___ = ___7_____<br \/>\nSo, 12 &#8211; 5 = ____7______<br \/>\nAnswer:<\/p>\n<p>12 &#8211; 2 = 10 we get 10<br \/>\n10 &#8211; 3 = 7<br \/>\n12 &#8211; 5 = 7<\/p>\n<p>Explanation:<br \/>\nTo solve 12 &#8211; 2\u00a0 and to get 10,<br \/>\nWe solve by using 2 counters in counter one we have 10 circles<br \/>\nand in next counter two we have 2 circles so in total we have 12,<br \/>\nNow in all we will strike 5 circles, 2 circles from counter-2 making equation<br \/>\nas 12 &#8211; 2 = 10 we got 10 in counter-1 and we strike 3 circles from counter-1<br \/>\nwe are left with 7 making it as 10 &#8211; 3 = 7, So in total we have taken 2 + 3 = 5<br \/>\nfrom 12 in 2-counters, making equation as 12 &#8211; 5 = 7 as shown in the picture.<\/p>\n<p>Question 2.<br \/>\n17 &#8211; 8 = ?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24724\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-44.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 44\" width=\"124\" height=\"112\" \/><br \/>\n17 &#8211; ___7___ = 10<br \/>\n10 &#8211; __1___ = ___9_____<br \/>\nSo, 17 &#8211; 8 = ___9_______<br \/>\nAnswer:<br \/>\n17 &#8211; 7 = 10<br \/>\n10 &#8211; 1 = 8<br \/>\nSo 17 &#8211; 8 = 9<\/p>\n<p>Explanation:<br \/>\nTo solve 17 -8\u00a0 and to get 10,<br \/>\nWe solve by using 2 counters in counter one we have 10 circles<br \/>\nand in next counter two we have 7 circles so in total we have 17,<br \/>\nNow in all we will strike 8 circles, 7 circles from counter-2 making equation<br \/>\nas 17 &#8211; 7 = 10 we got 10 in counter-1 and we strike 1 circle from counter-1<br \/>\nwe are left with 9 making it as 10 &#8211; 1 = 9, So in total we have taken 7 + 1 = 8<br \/>\nfrom 17 in 2-counters, making equation as 17 &#8211; 8 = 9 as shown in the picture.<\/p>\n<p><strong>Apply and Grow: Practice<\/strong><\/p>\n<p>Get to 10 to subtract<\/p>\n<p>Question 3.<br \/>\n16 &#8211; 7 = ?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24723\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-45.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 45\" width=\"123\" height=\"113\" \/><br \/>\nI6 &#8211; __6______ = 10<br \/>\n10 &#8211; ___1_____ = ____9____<br \/>\nSo, 16 &#8211; 7 = _____9_____ .<br \/>\nAnswer:<br \/>\n16 &#8211; 6 = 10<br \/>\n10 &#8211; 1 = 9<br \/>\nSo 16 &#8211; 7 = 9<\/p>\n<p>Explanation:<br \/>\nTo solve 16 -7\u00a0 and to get 10,<br \/>\nWe solve by using 2 counters in counter one we have 10 circles<br \/>\nand in next counter two we have 6 circles so in total we have 16,<br \/>\nNow in all we will strike 7 circles, 6 circles from counter-2 making equation<br \/>\nas 16 &#8211; 6 = 10 we got 10 in counter-1 and we strike 1 circle from counter-1<br \/>\nwe are left with 9 making it as 10 &#8211; 1 = 9, So in total we have taken 6 + 1 = 7<br \/>\nfrom 16 in 2-counters, making equation as 16 &#8211; 7 = 9 as shown in the picture.<\/p>\n<p>Question 4.<br \/>\n11 &#8211; 4 = ?<br \/>\n11 &#8211; ____1___ = 10<br \/>\n10 &#8211; ___3____ = ___7_____<br \/>\nSo, 11 &#8211; 4 = ___7_____ .<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-31507\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-13.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-13\" width=\"200\" height=\"145\" \/><\/p>\n<p>Answer:<br \/>\n11 &#8211; 1 = 10<br \/>\n10 &#8211; 3 = 7<br \/>\nSo 11 &#8211; 4 = 7<\/p>\n<p>Explanation:<br \/>\nTo solve 11 -4\u00a0 and to get 10,<br \/>\nWe solve by using 2 counters in counter one we have 10 circles<br \/>\nand in next counter two we have 1 circles so in total we have 11,<br \/>\nNow in all we will strike 4 circles, 1 circles from counter-2 making equation<br \/>\nas 11 &#8211; 1 = 10 we got 10 in counter-1 and we strike 3 circles from counter-1<br \/>\nwe are left with 9 making it as 10 &#8211; 3 = 7, So in total we have taken 1 + 3 = 4<br \/>\nfrom 11 in 2-counters, making equation as 11 &#8211; 4 = 7 as shown in the picture.<\/p>\n<p>Question 5.<br \/>\n13 &#8211; 5 = ?<br \/>\n13 &#8211; ____3_____ = 10<br \/>\n10 &#8211; ____2_____ = ____8______<br \/>\nSo, 13 &#8211; 5 = ____8____ .<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-31512\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-14.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-14\" width=\"200\" height=\"145\" \/><br \/>\n13 &#8211; 3 = 10<br \/>\n10 &#8211; 2 = 8<br \/>\nSo 13 &#8211; 5 = 8<\/p>\n<p>Explanation:<br \/>\nTo solve 13 -5\u00a0 and to get 10,<br \/>\nWe solve by using 2 counters in counter one we have 10 circles<br \/>\nand in next counter two we have 3 circles so in total we have 13,<br \/>\nNow in all we will strike 5 circles, 3 circles from counter-2 making equation<br \/>\nas 13 &#8211; 3 = 10 we got 10 in counter-1 and we strike 3 circles from counter-1<br \/>\nwe are left with 8 making it as 10 &#8211; 2 = 8, So in total we have taken 3 + 2 = 5<br \/>\nfrom 13 in 2-counters, making equation as 13 &#8211; 5 = 8 as shown in the picture.<\/p>\n<p>Question 6.<br \/>\n<strong>MP Number Sense<\/strong><br \/>\nWhich equations did Newton use to solve the problem?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24722\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-46.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 46\" width=\"483\" height=\"163\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-46.png 483w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-46-300x101.png 300w\" sizes=\"(max-width: 483px) 100vw, 483px\" \/><br \/>\nAnswer:<br \/>\nNewton uses Equation 3 : 12 &#8211; 2 =10 , 10 &#8211; 4 = 6 so we get 12 &#8211; 6 = 6<\/p>\n<p>Explanation:<br \/>\nIf we see picture we have two counters in total we have total 12 circles,<br \/>\nIn counter-2 we have 2 strike out means 12 &#8211; 2 = 10 and from counter-1<br \/>\nwe have 4 strike out so 10 &#8211; 4 = 6 so in total out of 12 we strike 6 making<br \/>\nthe equation as 12 &#8211; 6 = 6.<br \/>\nOut of three equations Newton uses equation 12 &#8211; 2 = 10 , 10 &#8211; 4 = 6,<br \/>\nother equations have 17 count in total and only 3rd equation is having<br \/>\n12 count as per the given picture, So newton use Equation 3.<\/p>\n<p><strong>Think and Grow: Modeling Real Life<\/strong><\/p>\n<p>Your friend checks out 13 books. You check out 4 fewer. How many books do you check out?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24721\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-47.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 47\" width=\"61\" height=\"116\" \/><br \/>\nModel:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24720\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-48.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 48\" width=\"128\" height=\"118\" \/><br \/>\nSubtraction equation:<\/p>\n<p>____9___ books<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-31544\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-15.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-15\" width=\"200\" height=\"145\" \/><br \/>\nI have checked 9 books.<\/p>\n<p>Explanation:<br \/>\nGiven my friend checks out 13 books and I check out 4 fewer,<br \/>\nMeans I will take 2 counters in counter-1 I will have 10 books and counter-2<br \/>\n3 books in total 13 books, now I have 4 fewer means I will strike out 4,<br \/>\n3 from counter-2 and 1 from counter-1 in total 4 from both the counters,<br \/>\nSo 13 &#8211; 4 = 9, I checked 9 books.<\/p>\n<p><strong>Show and Grow<\/strong><\/p>\n<p>Question 7.<br \/>\nYour friend skips 16 stones. You skip 8 fewer. How many stones do you skip?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24719\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-49.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 49\" width=\"161\" height=\"72\" \/><br \/>\nModel:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24718\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-50.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 50\" width=\"124\" height=\"116\" \/><br \/>\nSubtraction equation:<\/p>\n<p>_____8_______ stones<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-31551\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-16.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-16\" width=\"228\" height=\"159\" \/><br \/>\n16 &#8211; 8 = 8<br \/>\nSo I skip 8 stones.<\/p>\n<p>Explanation:<br \/>\nGiven my friend skips 16 stones and I skip 8 fewer,<br \/>\nMeans I will take 2 counters in counter-1 I will have 10 stones and counter-2<br \/>\n6 stones in total 16 stones, now I have 8 fewer means I will strike out 8 ,<br \/>\n6 from counter-2 and 2 from counter-1 in total 8 from both the counters,<br \/>\nSo 16 &#8211; 8 = 8, I skip 8 stones.<\/p>\n<h3><a id=\"Get_to_10_to_Subtract_Practice_5.4\"><\/a>Get to 10 to Subtract Practice 5.4<\/h3>\n<p>Get to 10 to Subtract<\/p>\n<p>Question 1.<br \/>\n15 &#8211; 6 = ?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24717\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-51.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 51\" width=\"123\" height=\"115\" \/><br \/>\n15 &#8211; __5_____ = 10<br \/>\n10 &#8211; ___1____ = __9______<br \/>\nSo, 15 &#8211; 6 = ____9____ .<br \/>\nAnswer:<br \/>\n15 &#8211; 5 = 10<br \/>\n10 -1 = 9<br \/>\nSo, 15 &#8211; 6 = 9.<\/p>\n<p>Explanation:<br \/>\nTo solve 15 -6\u00a0 and to get 10,<br \/>\nWe solve by using 2 counters in counter one we have 10 circles<br \/>\nand in next counter two we have 5 circles so in total we have 15,<br \/>\nNow in all we will strike 6 circles, 5 circles from counter-2 making equation<br \/>\nas 15 &#8211; 5 = 10 we got 10 in counter-1 and we strike 1 circle from counter-1<br \/>\nwe are left with 9 making it as 10 &#8211; 1 = 9, So in total we have taken 5 + 1 = 6<br \/>\nfrom 15 in 2-counters, making equation as 15 &#8211; 6 = 9 as shown in the picture.<\/p>\n<p>Question 2.<br \/>\n12 &#8211; 4 = ?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24716\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-52.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 52\" width=\"123\" height=\"113\" \/><br \/>\n12 &#8211; ___2____ = 10<br \/>\n10 &#8211; ___2____ = ___8_____<br \/>\nSo, 12 &#8211; 4 = ___8_____ .<br \/>\nAnswer:<br \/>\n12 &#8211; 2 = 10<br \/>\n10 -2 = 8<br \/>\nSo, 12 &#8211; 4 = 8.<\/p>\n<p>Explanation:<br \/>\nTo solve 12 -4\u00a0 and to get 10,<br \/>\nWe solve by using 2 counters in counter one we have 10 circles<br \/>\nand in next counter two we have 2 circles so in total we have 12,<br \/>\nNow in all we will strike 4 circles, 2 circles from counter-2 making equation<br \/>\nas 12 &#8211; 2 = 10 we got 10 in counter-1 and we strike 2 circles from counter-1<br \/>\nwe are left with 8 making it as 10 &#8211; 2 = 8, So in total we have taken 2 + 2 = 4<br \/>\nfrom 12 in 2-counters, making equation as 12 &#8211; 4 = 8 as shown in the picture.<\/p>\n<p>Question 3.<br \/>\n13 &#8211; 7 = ?<br \/>\n13 &#8211; ___3____ = 10<br \/>\n10 &#8211; ___4____ = ___6_____<br \/>\nSo, 13 &#8211; 7 = ____6____ .<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-31571\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-17.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-17\" width=\"200\" height=\"145\" \/><br \/>\n13 &#8211; 3 = 10<br \/>\n10 &#8211; 4 = 6<br \/>\n13 &#8211; 7 = 6<\/p>\n<p>Explanation:<br \/>\nTo solve 13 -7\u00a0 and to get 10,<br \/>\nWe solve by using 2 counters in counter one we have 10 circles<br \/>\nand in next counter two we have 3 circles so in total we have 13,<br \/>\nNow in all we will strike 7 circles, 3 circles from counter-2 making equation<br \/>\nas 13 &#8211; 3 = 10 we got 10 in counter-1 and we strike 4 circles from counter-1<br \/>\nwe are left with 6 making it as 10 &#8211; 4 = 6, So in total we have taken 3 + 4 = 7<br \/>\nfrom 13 in 2-counters, making equation as 13 &#8211; 7 = 6 as shown in the picture.<\/p>\n<p>Question 4.<br \/>\n14 &#8211; 8 = ?<br \/>\n14 &#8211; ___4____ = 10<br \/>\n10 &#8211; ___4____ = ___6_____<br \/>\nSo, 14 &#8211; 8 = ____6____ .<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-31576\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-18.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-18\" width=\"180\" height=\"128\" \/><br \/>\n14 &#8211; 4 = 10<br \/>\n10 &#8211; 4 = 6<br \/>\n14 &#8211; 8 = 6<\/p>\n<p>Explanation:<br \/>\nTo solve 14 -8\u00a0 and to get 10,<br \/>\nWe solve by using 2 counters in counter one we have 10 circles<br \/>\nand in next counter two we have 4 circles so in total we have 14,<br \/>\nNow in all we will strike 8 circles, 4 circles from counter-2 making equation<br \/>\nas 14 &#8211; 4 = 10 we got 10 in counter-1 and we strike 4 circles from counter-1<br \/>\nwe are left with 6 making it as 10 &#8211; 4 = 6, So in total we have taken 4 + 4 = 8<br \/>\nfrom 14 in 2-counters, making equation as 14 &#8211; 8 = 6 as shown in the picture.<\/p>\n<p>Question 5.<br \/>\n<strong>MP Number Sense<\/strong><br \/>\nWhich equations did Descartes use to solve the problem?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24715\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-53.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 53\" width=\"515\" height=\"168\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-53.png 515w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-53-300x98.png 300w\" sizes=\"(max-width: 515px) 100vw, 515px\" \/><br \/>\nAnswer:<\/p>\n<p>Descartes uses Equation 1 : 15 &#8211; 5 =10 , 10 &#8211; 4 = 6 so we get 15 &#8211; 9 = 6<\/p>\n<p>Explanation:<br \/>\nIf we see picture we have two counters in total we have total 15 circles,<br \/>\nIn counter-2 we have 5 strike out means 15 &#8211; 5 = 10 and from counter-1<br \/>\nwe have 4 strike out so 10 &#8211; 4 = 6 so in total out of 15 we strike 9 making<br \/>\nthe equation as 15 &#8211; 9 = 6.<br \/>\nOut of three equations Newton uses equation 15 &#8211; 5 = 10 , 10 &#8211; 4 = 6,<br \/>\nother equations have 20 count in total and only 1st equation is having<br \/>\n15 count as per the given picture, So newton use 1 Equation.<\/p>\n<p>Question 6.<br \/>\n<strong>Modeling Real Life<\/strong><br \/>\nYour friend recycles 14 cans. You recycle 7 fewer. How many cans do you recycle?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24714\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-54.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 54\" width=\"76\" height=\"91\" \/><br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24713\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-55.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 55\" width=\"122\" height=\"115\" \/><\/p>\n<p>____7_____ cans<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-31582\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-19.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-19\" width=\"180\" height=\"128\" \/><\/p>\n<p>I recycle 7 cans.<\/p>\n<p>Explanation:<br \/>\nGiven my friend recycle 14 cans and I recycle 7 fewer,<br \/>\nMeans I will take 2 counters in counter-1 I will have 10 cans and counter-2<br \/>\n4 cans in total 14 cans, now I have 7 fewer means I will strike out 7,<br \/>\n4 from the counter-2 and 3 from counter-1 in total 7 from both the counters,<br \/>\nSo 14 &#8211; 7 = 7, I recycle 7 cans.<\/p>\n<p><strong>Review &amp; Refresh<\/strong><\/p>\n<p>Is the equation true or false?<\/p>\n<p>Question 7.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24712\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-56.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 56\" width=\"144\" height=\"119\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-31595\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-20.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-20\" width=\"180\" height=\"128\" \/><br \/>\n3 + 2 = 5 + 0<br \/>\n5 = 5 ,<br \/>\nSo True.<\/p>\n<p>Explanation:<br \/>\nWe take 3 + 2 means adding 3 and 2 we get 3 + 2 = 5<br \/>\nand 5 + 0 is 5 so both sides are equal therefore<br \/>\n3 + 2 = 5 + 0 is True.<\/p>\n<p>Question 8.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24711\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-57.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 57\" width=\"140\" height=\"119\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-31597\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-21.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-21\" width=\"180\" height=\"128\" \/><br \/>\n8 &#8211; 2 = 6 \u2260 5 + 5 = 10<br \/>\n6 \u2260 10<br \/>\nSo False<\/p>\n<p>Explanation:<br \/>\nWe take 8 &#8211; 2 means subtracting 2 from 8 we get 8 &#8211; 2 = 6<br \/>\nand 5 + 5 means adding 5 and 5 we get 5 + 5\u00a0 =10,<br \/>\nIf we see both sides they are not equal as 6 \u2260 10,<br \/>\nSo 8 &#8211; 2 =\u00a05 + 5 is False.<\/p>\n<h3><a id=\"Lesson_5.5_More_True_or_False_Equations\"><\/a>Lesson 5.5 More True or False Equations<\/h3>\n<p><strong>Explore and Grow<\/strong><\/p>\n<p>Color the stars that have a sum or difference equal to 19 &#8211; 5.<\/p>\n<p><img loading=\"lazy\" class=\"alignnone size-full wp-image-24885\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-58.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 58\" width=\"487\" height=\"522\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-58.png 487w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-58-280x300.png 280w\" sizes=\"(max-width: 487px) 100vw, 487px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-31749\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-22.bmp\" alt=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-22.bmp\" width=\"487\" height=\"522\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-22.bmp 487w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-22-280x300.jpg 280w\" sizes=\"(max-width: 487px) 100vw, 487px\" \/><br \/>\nExplanation:<br \/>\nWe color the stars that have a sum or difference equal to 19 &#8211; 5,<br \/>\nmeans\u00a0 19 &#8211; 5 = 14, We check each star if equal to 14 we will color.<br \/>\na. The sum is 9 + 5 = 14, so color it with green,<br \/>\nb. The difference is 20 &#8211; 6 = 14, we color it with blue<br \/>\nc. The sum is 12 + 1 + 1 = 14, we color it with green<br \/>\nd. The difference is 16 &#8211; 2 = 14, we color it with blue<br \/>\ne. The difference is 13 &#8211; 1 = 12 , we will not color it<br \/>\nas this is not equal to 14.<br \/>\nf. The sum is 14 + 0 = 14 , we will color it with green<\/p>\n<p><strong>Show and Grow<\/strong><\/p>\n<p>Is the equation true or false ?<\/p>\n<p>Question 1.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24884\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-59.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 59\" width=\"439\" height=\"116\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-59.png 439w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-59-300x79.png 300w\" sizes=\"(max-width: 439px) 100vw, 439px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-31756\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-23.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-23\" width=\"486\" height=\"166\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-23.bmp 486w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-23-300x102.jpg 300w\" sizes=\"(max-width: 486px) 100vw, 486px\" \/><br \/>\nAs 17 &#8211; 9 = 8 \u00a0\u2260 14 -5 = 9<br \/>\nSo False<\/p>\n<p>Explanation:<br \/>\nWe take 17 &#8211; 9 means subtracting 9 from 17 we get 17 &#8211; 9 = 8<br \/>\nand 14 &#8211; 5 means subtracting 5 from 14 we get 14 &#8211; 5 = 9,<br \/>\nIf we see both sides they are not equal as 8 \u2260 9,<br \/>\nSo 17 &#8211; 9 =\u00a014 &#8211; 5 is False.<\/p>\n<p>Question 2.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24883\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-60.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 60\" width=\"444\" height=\"116\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-60.png 444w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-60-300x78.png 300w\" sizes=\"(max-width: 444px) 100vw, 444px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-31951\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-24.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-24\" width=\"486\" height=\"166\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-24.bmp 486w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-24-300x102.jpg 300w\" sizes=\"(max-width: 486px) 100vw, 486px\" \/><br \/>\nAs 6 + 5 = 11 = 18 &#8211; 7 = 11<br \/>\nSo True.<\/p>\n<p>Explanation:<br \/>\nWe take 6 + 5 means adding 6 and 5 we get 6 + 5 = 11,<br \/>\nand 18 &#8211; 7 means subtracting 7 from 18 we get 18 &#8211; 7 = 11,<br \/>\nAs both sides are equal therefore<br \/>\n6 + 5 = 11 = 18 &#8211; 7 = 11 is True<\/p>\n<p><strong>Apply and Grow: Practice<\/strong><\/p>\n<p>Is the equation true or false?<\/p>\n<p>Question 3.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24882\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-61.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 61\" width=\"429\" height=\"110\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-61.png 429w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-61-300x77.png 300w\" sizes=\"(max-width: 429px) 100vw, 429px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-31961\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-25-1.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-25\" width=\"486\" height=\"123\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-25-1.bmp 486w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-25-1-300x76.jpg 300w\" sizes=\"(max-width: 486px) 100vw, 486px\" \/><\/p>\n<p>As 5 + 7 = 12\u00a0 \u2260\u00a0 3 + 8 = 11<br \/>\nSo False<\/p>\n<p>Explanation:<br \/>\nWe take 5 + 7 means adding 5 and 7 we get 5 + 7 = 12,<br \/>\nand 3 + 8 means adding 3 and 8 we get 3 + 8 = 11,<br \/>\nAs both sides are not equal therefore<br \/>\n5 + 7 = 12 \u2260 3 + 8 = 11 is False.<\/p>\n<p>Question 4.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24881\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-62.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 62\" width=\"470\" height=\"111\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-62.png 470w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-62-300x71.png 300w\" sizes=\"(max-width: 470px) 100vw, 470px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-31960\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-26.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-26\" width=\"533\" height=\"124\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-26.bmp 533w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-26-300x70.jpg 300w\" sizes=\"(max-width: 533px) 100vw, 533px\" \/><br \/>\nAs 4 + 9 = 13 = 5 + 3 + 5 = 13<br \/>\nIs True.<\/p>\n<p>Explanation:<br \/>\nWe take 4 + 9 means adding 4 and 9 we get 4 + 9 = 13,<br \/>\nand 5 + 3 + 5\u00a0 means adding 5 , 3 and 5 we get 5 + 3 + 5 = 13,<br \/>\nAs both sides are equal therefore<br \/>\n4 + 9 = 13 = 5 + 3 + 5 = 13 is True.<\/p>\n<p>Question 5.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24880\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-63.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 63\" width=\"163\" height=\"110\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-31964\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-27.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-27\" width=\"189\" height=\"120\" \/><\/p>\n<p>As 12 &#8211; 7 = 5 \u2260 13 &#8211; 5 = 8<br \/>\nSo False.<\/p>\n<p>Explanation:<br \/>\nWe take 12 &#8211; 7 means subtracting 7 from 12 we get 12 &#8211; 7 = 5,<br \/>\nand 13 &#8211; 5 means subtracting 5 from 13 we get 13 &#8211; 5 = 8,<br \/>\nAs both sides are not equal therefore<br \/>\n12 &#8211; 7\u00a0 = 5 \u2260 13 &#8211; 5 = 8 is False.<\/p>\n<p>Question 6.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24877\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-66.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 66\" width=\"157\" height=\"106\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-31966\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-28.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-28\" width=\"189\" height=\"120\" \/><\/p>\n<p>As 14 &#8211; 8 = 6 = 12 &#8211; 6 = 6<br \/>\nSo True.<\/p>\n<p>Explanation:<br \/>\nWe take 14 &#8211; 8 means subtracting 8 from 14 we get 14 &#8211; 8 = 6,<br \/>\nand 12 &#8211; 6 means subtracting 6 from 12 we get 12 &#8211; 6 = 6,<br \/>\nAs both sides are equal therefore<br \/>\n14 &#8211; 8\u00a0 = 6 = 12 &#8211; 6 = 6 is True.<\/p>\n<p>Question 7.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24879\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-64.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 64\" width=\"154\" height=\"106\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-31967\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-29.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-29\" width=\"189\" height=\"120\" \/><br \/>\n1 + 8 = 9 = 16 -7 = 9<br \/>\nSo True.<\/p>\n<p>Explanation:<br \/>\nWe take 1 + 8\u00a0 means adding 1 and 8 we get 1 + 8\u00a0 = 9,<br \/>\nand 16 &#8211; 7 means subtracting 7 from 16 we get 16 &#8211; 7 = 9,<br \/>\nAs both sides are equal therefore<br \/>\n1 + 8\u00a0 = 9 = 16 &#8211; 7 = 9 is True.<\/p>\n<p>Question 8.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24878\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-65.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 65\" width=\"188\" height=\"106\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-31969\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-30.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-30\" width=\"189\" height=\"120\" \/><br \/>\n18 &#8211; 9 = 9 \u2260\u00a0 5 + 1 + 4 = 10<br \/>\nSo False.<\/p>\n<p>Explanation:<br \/>\nWe take 18 &#8211; 9\u00a0 means subtracting 9 from 18 we get 18 &#8211; 9\u00a0 = 9,<br \/>\nand 5 + 1 + 4 means adding 5,1 and 4 we get 5 + 1 + 4 = 10,<br \/>\nAs both sides are not equal therefore<br \/>\n18 &#8211; 9\u00a0 = 9 \u2260 5 + 1 + 4 = 10 is False.<\/p>\n<p>Question 9.<br \/>\n<strong>MP Number Sense<\/strong><br \/>\nCircle all of the equations that are true.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24876\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-67.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 67\" width=\"506\" height=\"32\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-67.png 506w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-67-300x19.png 300w\" sizes=\"(max-width: 506px) 100vw, 506px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-31970\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-31.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-31\" width=\"518\" height=\"77\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-31.bmp 518w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-31-300x45.jpg 300w\" sizes=\"(max-width: 518px) 100vw, 518px\" \/><\/p>\n<p>Explanation:<br \/>\nGiven equations are a. 20 = 2 as 20 is not equal to 2,false so we will not circle,<br \/>\nb. 19 &#8211; 7 = 12 as 19 &#8211; 7 is 12 this is true we will circle it.<br \/>\nc. 6 + 6 + 3 = 7 + 8 as 6 + 6 + 3 = 15 and 7 + 8 = 15, Both are same<br \/>\nand true we will circle the equation.<\/p>\n<p><strong>Think and Grow: Modeling Real Life<\/strong><\/p>\n<p>You hove 12 lemons. You use 4 of them. Your friend has 3 lemons and buys 4 more.<br \/>\nDo you each have the same number of lemons?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24875\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-68.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 68\" width=\"121\" height=\"153\" \/><br \/>\nEquation:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24874\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-69.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 69\" width=\"263\" height=\"173\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-31971\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-32.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-32\" width=\"266\" height=\"157\" \/><br \/>\nNo each do not have the same number of lemons as 8 \u2260 7 .<\/p>\n<p>Explanation:<br \/>\nGiven I have 12 lemons and use 4 of them means 12 &#8211; 4<br \/>\nMy friend have 3 lemons and buys 4 more means 3 + 4<br \/>\nnow checking both of them 12 &#8211; 4 = 8 and 3 + 4 = 7 as 8 \u2260 7<br \/>\nboth are not equal each do not have the same number of lemons.<\/p>\n<p><strong>Show and Grow<\/strong><\/p>\n<p>Question 10.<br \/>\nYou have 14 grapes. You eat 7 of them. Your friend has 10 grapes and eats 3 of them.<br \/>\nDo you each have the same number of grapes?<br \/>\nEquation:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24873\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-70.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 70\" width=\"265\" height=\"177\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-31972\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-34.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-34\" width=\"266\" height=\"138\" \/><br \/>\nYes each have the same number of grapes as 7 = 7.<\/p>\n<p>Explanation:<br \/>\nGiven I have 14 grapes and I eat 7 of them means 14 -7<br \/>\nMy friend has 10 grapes and eats 3 of them means 10 &#8211; 3,<br \/>\nNow checking both we have 14 &#8211; 7 = 7 and 10 &#8211; 3 = 7,<br \/>\nBoth are equal, So, Yes each of them have the same number of grapes 7= 7.<\/p>\n<h3><a id=\"More_True_or_False_Equations_Homework_&amp;_Practice_5.5\"><\/a>More True or False Equations Practice 5.5<\/h3>\n<p>Is the equation true or false?<\/p>\n<p>Question 1.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24872\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-71.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 71\" width=\"440\" height=\"106\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-71.png 440w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-71-300x72.png 300w\" sizes=\"(max-width: 440px) 100vw, 440px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-32239\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-35.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-35\" width=\"435\" height=\"138\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-35.bmp 435w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-35-300x95.jpg 300w\" sizes=\"(max-width: 435px) 100vw, 435px\" \/><br \/>\n13 &#8211; 9 = 4 = 11 &#8211; 7 = 4<br \/>\nSo True.<\/p>\n<p>Explanation:<br \/>\nChecking 13 &#8211; 9 and 11 &#8211; 7 , subtracting 9 from 13 we get 4<br \/>\nand subtracting 7 from 11 we get 4<br \/>\nas both equations values are equal, true.<\/p>\n<p>Question 2.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24871\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-72.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 72\" width=\"223\" height=\"80\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-32274\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-36.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-36\" width=\"244\" height=\"102\" \/><br \/>\n9 + 8 = 17 = 17 + 0 = 17<br \/>\nSo True.<\/p>\n<p>Explanation:<br \/>\nChecking 9 + 8 and 17 + 0, as 9 + 8 = 17 and<br \/>\n17 + 0 = 17 as both equations values are equal to 17 so true.<\/p>\n<p>Question 3.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24870\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-73.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 73\" width=\"224\" height=\"75\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-32278\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-37.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-37\" width=\"244\" height=\"102\" \/><br \/>\n12 &#8211; 4 = 8 \u2260 15 &#8211; 6 = 9,<br \/>\nSo False.<\/p>\n<p>Explanation:<br \/>\nChecking 12 &#8211; 4 and 15 &#8211; 6, We get 12 &#8211; 4 = 8 and<br \/>\n15 &#8211; 6 = 9 as both equations values are not equal 8 \u2260 9,<br \/>\nSo false.<\/p>\n<p>Question 4.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24869\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-74.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 74\" width=\"225\" height=\"77\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-32280\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-38.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-38\" width=\"244\" height=\"102\" \/><br \/>\n4 + 5 = 9 \u2260 11 &#8211; 3 = 8<br \/>\nIs False<\/p>\n<p>Explanation:<br \/>\nChecking 4 + 5 and 11 &#8211; 3, We get 4 + 5 = 9 and<br \/>\n11 &#8211; 3 = 8 as both equations values are not equal 9 \u2260 8,<br \/>\nSo false.<\/p>\n<p>Question 5.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24868\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-75.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 75\" width=\"223\" height=\"77\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-32283\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-39-1.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-39\" width=\"244\" height=\"102\" \/><br \/>\n15 &#8211; 7 = 8 = 4 + 4 = 8<br \/>\nSo True.<\/p>\n<p>Explanation:<br \/>\nChecking 15 &#8211; 7 and\u00a0 4 + 4\u00a0 we get 15 &#8211; 7 = 8<br \/>\nand\u00a0 4 + 4 = 8 as both equations values are same 8 = 8<br \/>\nso true.<\/p>\n<p>Question 6.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24867\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-76.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 76\" width=\"193\" height=\"120\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-32285\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-40.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-40\" width=\"244\" height=\"120\" \/><br \/>\n0 + 5 + 2 = 7 = 12 &#8211; 5 =\u00a0 7<br \/>\nSo True.<\/p>\n<p>Explanation:<br \/>\nChecking 0 + 5 + 2 = 12 &#8211; 5, We get 0 + 5 + 2 = 7<br \/>\nand 12 &#8211; 5 = 7 as both equations values are same 7 = 7<br \/>\nso true.<\/p>\n<p>Question 7.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24866\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-77.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 77\" width=\"191\" height=\"124\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-32287\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-41.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-41\" width=\"244\" height=\"135\" \/><br \/>\n16 &#8211; 8 = 8\u00a0 \u2260\u00a0 2 + 3 + 2 = 7<br \/>\nSo False<\/p>\n<p>Explanation:<br \/>\nChecking 16 &#8211; 8 and 2 + 3 + 2 we see 16 &#8211; 8 = 8<br \/>\nand\u00a0 2 + 3 + 2 = 7 as both equations are not equal<br \/>\n8 \u2260 7 so false.<\/p>\n<p>Question 8.<br \/>\n<strong>MP Number Sense<\/strong><br \/>\nCircle all of the equations that are false.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24865\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-78.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 78\" width=\"502\" height=\"36\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-78.png 502w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-78-300x22.png 300w\" sizes=\"(max-width: 502px) 100vw, 502px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-32291\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-42.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-42\" width=\"526\" height=\"79\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-42.bmp 526w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-42-300x45.jpg 300w\" sizes=\"(max-width: 526px) 100vw, 526px\" \/><br \/>\nExplanation:<br \/>\nChecking equations<br \/>\na. 7 + 2 = 9 and 11 -2 = 9 both are equal so true we will not circle.<br \/>\nb. 3 , 12 &#8211; 8 = 4 as 3 \u2260\u00a0 4, So false we will circle it.<br \/>\nc. 4 + 1 + 4 = 9 and 14 -6 = 12 as 9 \u2260 12 , So false we will circle it.<\/p>\n<p>Question 9.<br \/>\n<strong>Modeling Real Life<\/strong><br \/>\nYou have 9 badges. You earn 3 more. Your friend has 5 badges and earns 7 more. Do you each have the same number of badges?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24864\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-79.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 79\" width=\"92\" height=\"99\" \/><br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24863\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answer-Key-Grade-1-Chapter-5-Subtract-Numbers-within-20-80.png\" alt=\"Big Ideas Math Answer Key Grade 1 Chapter 5 Subtract Numbers within 20 80\" width=\"266\" height=\"133\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-32293\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-43.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-43\" width=\"280\" height=\"145\" \/><br \/>\nYes , each have the same number of badges.<\/p>\n<p>Explanation:<br \/>\nGiven I have 9 badges and\u00a0 earn 3 more means 9 + 3 = 12,<br \/>\nMy friend has 5 badges and earns 7 more means 5 + 7 = 12,<br \/>\nas both are having 12 badges Yes, I and my friend each<br \/>\nhave same number of badges .<\/p>\n<p><strong>Review &amp; Refresh<\/strong><\/p>\n<p>Question 10.<br \/>\n_____4____ + 2 = 6<br \/>\nAnswer:<br \/>\n4 + 2 = 6<\/p>\n<p>Explanation:<br \/>\nGiven _______ + 2 = 6, Let us take missing number as X,<br \/>\nX + 2 = 6 means X = 6 &#8211; 2 = 4, X = 4 So missing number is 4,<br \/>\nthe equation is 4 + 2 = 6.<\/p>\n<p>Question 11.<br \/>\n____6____ + 3 = 9<br \/>\nAnswer:<br \/>\n6 + 3 = 9<\/p>\n<p>Explanation:<br \/>\nGiven _______ + 3 = 9, Let us take missing number as X,<br \/>\nX + 3 = 9 means X = 9 &#8211; 3 = 6, X = 6 So missing number is 6,<br \/>\nthe equation is 6 + 3 = 9.<\/p>\n<h3><a id=\"Lesson_5.6_Make_True_Equations\"><\/a>Lesson 5.6 Make True Equations<\/h3>\n<p><strong>Explore and Grow<\/strong><\/p>\n<p>Complete the equation.<\/p>\n<p>14 &#8211; 5 = 3 + __________<\/p>\n<p><img loading=\"lazy\" class=\"alignnone size-full wp-image-25007\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-81.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 5 Subtract Numbers within 20 81\" width=\"433\" height=\"257\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-81.png 433w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-81-300x178.png 300w\" sizes=\"(max-width: 433px) 100vw, 433px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-32306\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-44.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-44\" width=\"445\" height=\"257\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-44.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-44-300x173.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><br \/>\n14 &#8211; 5 = 3 + 6<\/p>\n<p>Explanation:<br \/>\nGiven 14 &#8211; 5 = 3 + ________ Let us take missing number as X,<br \/>\nFirst we see 14 &#8211; 5 on number line we move<br \/>\n5 steps left from 14 we get 9, means 3 + X = 9<br \/>\nso to get X we move on number line from 3 till 9<br \/>\nwe got 6 units means X = 6,<br \/>\ntherefore the true equation is 14 &#8211; 5 = 3 + 6.<\/p>\n<p><strong>Show and Grow<\/strong><\/p>\n<p>Question 1.<br \/>\n? + 6 = 10 &#8211; 3<br \/>\n? + 6 = __7______<br \/>\n___1_____ + 6 = ___7____<\/p>\n<p>So, ____1____ + 6 = 10 &#8211; 3.<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-32310\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-45-1.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-45\" width=\"445\" height=\"263\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-45-1.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-45-1-300x177.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><br \/>\n1 + 6 = 10 &#8211; 3<\/p>\n<p>Explanation:<br \/>\nGiven _____ + 6 = 10 &#8211; 3<br \/>\nNow first we start from 10 and move 3 units back on the<br \/>\nnumber line we get 7, 10 &#8211; 3 = 7 now from 6 we will move<br \/>\nright till we get 7 we moved 1 unit means 6 + 1\u00a0 = 7,<br \/>\nSo the true equation is 1 + 6 = 10 &#8211; 3.<\/p>\n<p>Question 2.<br \/>\n12 &#8211; 9 = ? &#8211; 5<br \/>\n____3____ = ? &#8211; 5<br \/>\n____3____ = __8_____ &#8211; 5<\/p>\n<p>So, 12 &#8211; 9 = ____8____ &#8211; 5.<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-32312\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-46.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-46\" width=\"445\" height=\"263\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-46.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-46-300x177.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><br \/>\n12 &#8211; 9 = 8 &#8211; 5<\/p>\n<p>Explanation:<br \/>\nFirst we find 12 &#8211; 9 we start from 12 on number line<br \/>\nand move 9 units back we get 3 means 12 &#8211; 9 = 3 and ____ &#8211; 5 = 3,<br \/>\nLet us take missing number as X and X &#8211; 5 = 3 , therefore X = 3 + 5<br \/>\non number line we move 3 units right from 5 we get 8,<br \/>\nmaking the true equation as 12 &#8211; 9 = 8 &#8211; 5.<\/p>\n<p><strong>Apply and Grow: Practice<\/strong><\/p>\n<p>Question 3.<br \/>\n? + 8 = 9 + 6<br \/>\n? + 8 = __15______<br \/>\n____7____ + 8 = _15___<\/p>\n<p>So, ___7_____ + 8 = 9 + 6.<br \/>\nAnswer:<br \/>\n_ + 8 = 9 + 6<br \/>\n_ + 8 = 15<br \/>\n7 + 8 = 15<br \/>\nSo 7 + 8 = 9 + 6<\/p>\n<p>Explanation :<\/p>\n<p>Given ___ +\u00a0 8 = 9 + 6, First we see 9 + 6 = 15 means<br \/>\n____ + 8 = 15 So let us take missing number as X ,<br \/>\nX + 8 = 15 therefore X = 15 &#8211; 8 = 7 making true equation as<br \/>\n7 + 8 = 9 + 6.<\/p>\n<p>Question 4.<br \/>\n13 &#8211; 8 = ? &#8211; 6<br \/>\n___5_____ = ? &#8211; 6<br \/>\n____5____ = __11_ &#8211; 6<\/p>\n<p>So, 13 &#8211; 8 = __11_ &#8211; 6.<br \/>\nAnswer:<br \/>\n13 &#8211; 8 = _______ &#8211; 6<br \/>\n5 = ______ &#8211; 6<br \/>\n5 = 11 &#8211; 6<br \/>\nSo 13 &#8211; 8 = 11 &#8211; 6<\/p>\n<p>Explanation:<br \/>\nGiven 13 &#8211; 8 = ____ &#8211; 6 means first we see 13 &#8211; 8 we get 5<br \/>\nmeans _____ &#8211; 6 = 5 let us take missing number as X<br \/>\nSo X &#8211; 6 = 5, X = 5 + 6 = 11 making the true equation as<br \/>\n13 &#8211; 8\u00a0 = 11 &#8211; 6.<\/p>\n<p>Question 5.<br \/>\n14 &#8211; 6 = ? + 2<br \/>\n___8_____ = ? + 2<br \/>\n____8____ = ___6____ + 2<\/p>\n<p>So, 14 &#8211; 6 = ____6____ + 2.<br \/>\nAnswer:<br \/>\n14 &#8211; 6 = _____ + 2<br \/>\n8 = ________ + 2<br \/>\n8 = 6 + 2<br \/>\nSo 14 &#8211; 6 = 6 + 2<\/p>\n<p>Explanation:<br \/>\nGiven 14 &#8211; 6 is equal to ________ + 2 , first we see 14 &#8211; 6 we get<br \/>\n8 means _______ + 2 = 8 , let us take missing number as X<br \/>\nso 8 = X + 2 means X = 8 &#8211; 2 = 6 making the true equation as<br \/>\n14 &#8211; 6 = 6 + 2.<\/p>\n<p>Question 6.<br \/>\n15 &#8211; ? = 3 + 3<br \/>\n15 &#8211; ? = __6______<br \/>\n15 &#8211; ___9_____ = ___6____<\/p>\n<p>So, 15 &#8211; ____9____ = 3 + 3.<br \/>\nAnswer:<br \/>\n15 &#8211; ___ = 3 + 3<br \/>\n15 &#8211; ___ =\u00a0 6<br \/>\n15 &#8211; 9 = 6<br \/>\n15 &#8211; 9 = 3 + 3<\/p>\n<p>Explanation:<br \/>\nGiven 15 &#8211; ___ = 3 + 3 means first we see 3 + 3 = 6,<br \/>\nmeans 15 &#8211; __ = 6 , Let us take X as missing number means<br \/>\n15 &#8211; X = 6 we get X = 15 &#8211; 6 = 9\u00a0 therefore 15- 9 = 6,<br \/>\nmaking true equation as 15 &#8211; 9 = 3 + 3.<\/p>\n<p>Question 7.<br \/>\n_____12_____ &#8211; 6 = 3 + 2 + 1<br \/>\nAnswer:<br \/>\n12 &#8211; 6 = 3 + 2 + 1<\/p>\n<p>Explanation:<br \/>\nGiven __________ &#8211; 6 = 3 + 2 + 1 we see first<br \/>\n3 + 2 + 1 = 6 means ________ &#8211; 6 = 6,<br \/>\nlet us take missing number as X , X &#8211; 6 = 6,<br \/>\nX = 6 + 6 = 12 making the true equation as 12 &#8211; 6 = 3 + 2 + 1.<\/p>\n<p>Question 8.<br \/>\n6 + 4 + 4 = 6 + _______<br \/>\nAnswer:<br \/>\n6 + 4 + 4 = 6 + 8<\/p>\n<p>Explanation:<br \/>\nGiven 6 + 4 + 4 = 6 + _______, First we add 6 + 4 + 4 we get 14<br \/>\nmeans 14 = 6 + ____, we will take missing number as X So that<br \/>\n6 + X = 14 , X = 14 &#8211; 6 = 8 making the true equation as 6 + 4 + 4 = 6 + 8.<\/p>\n<p>Question 9.<br \/>\n<strong>YOU BE THE TEACHER<\/strong><br \/>\nNewton says 2 makes the equation true. Is Newton correct? Show how you know.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-25005\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-82.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 5 Subtract Numbers within 20 82\" width=\"144\" height=\"151\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-32362\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-47.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-47\" width=\"445\" height=\"263\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-47.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-47-300x177.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><br \/>\nYes, Newton is correct, as 7 + 2 = 9 = 11 &#8211; 2.<\/p>\n<p>Explanation:<br \/>\nGiven the equation as 7 + 2 = 11 -____ and newton says 2<br \/>\nmakes the equation true, First we see 7 + 2 = 9<br \/>\non number line we move 2 steps from 7 we get 9 so<br \/>\nnow on number line we need to reach 9\u00a0 from 11<br \/>\nso we will move 2 steps back or left we reach 9 so 11 &#8211; 2 = 9,<br \/>\nBoth equations are equal so Newton is true.<\/p>\n<p><strong>Think and Grow: Modeling Real Life<\/strong><\/p>\n<p>You catch 11 butterflies. 4 fly away. Your friend catches 3 butterflies.<br \/>\nHow many more butterflies must your friend catch to have the same number as you?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-25003\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-83.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 5 Subtract Numbers within 20 83\" width=\"156\" height=\"182\" \/><br \/>\nEquation:<br \/>\n___11____ &#8211; ___4_____ = ____3___ + ?<\/p>\n<p>____4______ butterflies<\/p>\n<p>11 &#8211; 4\u00a0 = 3 + 4<br \/>\nMy friend should catch 4 butterflies to have same number as me.<\/p>\n<p>Explanation :<br \/>\nGiven I catch 11 butterflies. 4 fly away means I have<br \/>\n11 &#8211; 4 = 7 butterflies now and my friend catches 3 butterflies<br \/>\nto have same number of butterflies let my friend should catch<br \/>\nX butterflies as 3 + X = 7 so X = 7 &#8211; 3 = 4 making equation as<br \/>\n11 &#8211; 4 = 3 + 4. Therefore my friend should catch 4 butterflies<br \/>\nto have same number as me.<\/p>\n<p><strong>Show and Grow<\/strong><\/p>\n<p>Question 10.<br \/>\nYou catch 15 leaves. 6 of them blow away. Your friend catches 12 leaves and some of them blow away. Now you each have the same number of leaves. How many of your friend\u2019s leaves blow away?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-25001\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-84.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 5 Subtract Numbers within 20 84\" width=\"110\" height=\"93\" \/><br \/>\nEquation:<br \/>\n___15____ &#8211; ___6_____ = ___12____ &#8211; ?<\/p>\n<p>______3____ leaves<br \/>\n15 &#8211; 6 = 12 &#8211; 3,<br \/>\n3 leaves of my friend\u2019s blow away.<\/p>\n<p>Explanation:<br \/>\nGiven I catch 15 leaves and 6 of them blow away means I have<br \/>\n15 &#8211; 6 = 9, Your friend catches 12 leaves and some of them blow away<br \/>\nlets take it as X number\u00a0and given I\u00a0&amp; my friend have same number of leaves now<br \/>\n12 &#8211; X = 9 , X = 12 &#8211; 9 = 3. So 3 leaves of my friend\u2019s blow away.<\/p>\n<h3><a id=\"Make_True_Equations_Practice_5.6\"><\/a>Make True Equations Practice 5.6<\/h3>\n<p>Question 1.<br \/>\n12 &#8211; ? = 8 &#8211; 4<br \/>\n12 &#8211; ? = __4______<br \/>\n12 &#8211; ___8_____ = ___4____<\/p>\n<p>So, 12 &#8211; ___4_____ = 8 &#8211; 4.<br \/>\nAnswer:<br \/>\n12 &#8211; ____ = 8 &#8211; 4<br \/>\n12 &#8211; ___ = 4<br \/>\n12 &#8211; 8 = 4<br \/>\nSo, 12 &#8211; 8 =\u00a0 8 &#8211; 4<\/p>\n<p>Explanation:<br \/>\nGiven equation as 12 &#8211; ___ = 8 &#8211; 4, first we see 8 &#8211; 4<br \/>\nwe get as 4, 8-4 = 4 So 12 &#8211; ___ = 4,<br \/>\nLet us take missing number as X so 12 &#8211; X = 4,<br \/>\nX = 12 &#8211; 4= 8, Now the true equation is 12 &#8211; 8 = 8 &#8211; 4.<\/p>\n<p>Question 2.<br \/>\n7 + 9 = 8 + ?<br \/>\n____16____ = 8 + ?<br \/>\n_____16___ = 8 + ___8____<\/p>\n<p>So, 7 + 9 = 8 + ___8_____ .<br \/>\n7 + 9 = 8 + ___<br \/>\n16 = 8 + ___<br \/>\n16 = 8 + 8<br \/>\nSo, 7 + 9 = 8 + 8<\/p>\n<p>Explanation:<br \/>\nGiven equation as 7 + 9 = 8 + __,\u00a0 So first we see<br \/>\n7 + 9 = 16 means 8 + ___ = 16 ,Let us take X as missing number<br \/>\n8 + X = 16, X = 16 &#8211; 8\u00a0 = 8, Now the true equation is 7 + 9 = 8 + 8<\/p>\n<p>Question 3.<br \/>\n4 + 3 = __________ &#8211; 7<br \/>\nAnswer:<br \/>\n4 + 3 = 14 &#8211; 7<\/p>\n<p>Explanation:<br \/>\nGiven 4 + 3 = ___ &#8211; 7, first we see 4 + 3 we get 7,<br \/>\nmeans 7\u00a0 = ____ &#8211; 7, Let us take X as missing number<br \/>\nso 7 = X &#8211; 7, X = 7 + 7 = 14 making true equation as<br \/>\n4 + 3 = 14 &#8211; 7.<\/p>\n<p>Question 4.<br \/>\n7 + _________ = 17 &#8211; 0<br \/>\nAnswer:<br \/>\n7 + 10 = 17 &#8211; 0<\/p>\n<p>Explanation:<br \/>\nGiven as 7 + ___ = 17 &#8211; 0 first we see 17 &#8211; 0 we get 17<br \/>\nmeans 7 + ___ = 17, Now we take missing number as X,<br \/>\n7 + X = 17, X = 17 &#8211; 7 = 10 therefore the true equation is<br \/>\n7 + 10 = 17 &#8211; 0.<\/p>\n<p>Question 5.<br \/>\n__________ + 20 = 8 + 10 + 2<br \/>\nAnswer:<br \/>\n0 + 20 = 8 + 10 + 2<\/p>\n<p>Explanation:<br \/>\nGiven ____ + 20 = 8 + 10 + 2, We solve first 8 + 10 + 2<br \/>\nwe get 20 so\u00a0 ____ + 20 = 20, Let us take missing number as X,<br \/>\nX + 20 = 20 therefore X = 20 -20 = 0 , Making true equation as<br \/>\n0 + 20 = 8 + 10 + 2.<\/p>\n<p>Question 6.<br \/>\n3 + 1 + 1 = 14 &#8211; __________<br \/>\nAnswer:<br \/>\n3 + 1 + 1 = 14 &#8211; 9<\/p>\n<p>Explanation:<\/p>\n<p>Given 3 + 1 + 1 = 14 &#8211; ____, first we see 3 + 1 + 1 we get<br \/>\n5 and 14 &#8211; ___ = 5 , Let us take missing number as X, 14 &#8211; X = 5,<br \/>\nX = 14 &#8211; 5 = 9, making true equation as 3 + 1 + 1 = 14 &#8211; 9.<\/p>\n<p>Question 7.<br \/>\n<strong>YOU BE THE TEACHER<\/strong><br \/>\nDescartes says 5 makes the equation true. Is Descartes correct? Show how you know.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24999\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-85.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 5 Subtract Numbers within 20 85\" width=\"136\" height=\"150\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-32381\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-48.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-48\" width=\"445\" height=\"263\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-48.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-48-300x177.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><br \/>\n17 &#8211; 9 \u2260 5 &#8211; 2 ,So Descartes is in correct.<\/p>\n<p>Explanation:<br \/>\nGiven equation is 17 &#8211; 9 = ___ &#8211; 2 and 5 makes the equation true ,<br \/>\nwe see first 17 &#8211; 9 on number line we start from 17 and move 9 units back<br \/>\nwe get 8 means 17 &#8211; 9 = 8, Now we take as per Descartes 5 &#8211; 2 on number line<br \/>\nwe start from 5 and move 2 units back we get 3 which is not equal to 8,<br \/>\nSo 17 &#8211; 9 \u2260 5 &#8211; 2 ,So Descartes is in correct.<\/p>\n<p>Question 8.<br \/>\nModeling Real Life<br \/>\nYou catch 14 fireflies. You lose 8 of them. Your friend catches 11 fireflies and loses some of them.<br \/>\nNow you each have the same number of fireflies. How many fireflies does your friend lose?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24998\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-86.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 5 Subtract Numbers within 20 86\" width=\"63\" height=\"82\" \/><br \/>\n___14_____ &#8211; ___8____ = ___11____ &#8211; ?<\/p>\n<p>__5_____ fireflies<br \/>\n14 &#8211; 8 = 11 &#8211; 5, My friend loses 5 fireflies.<\/p>\n<p>Explanation:<br \/>\nGiven I catch 14 fireflies and lose 8 of them, means I have<br \/>\n14 &#8211; 8 = 6 with me, My friend catches 11 fireflies and<br \/>\nloses some of them let us take my friend loses X fireflies and<br \/>\neach have the same number of fireflies means 11 &#8211; X = 6, So<br \/>\nX = 11 &#8211; 6 = 5, making the equation as 14 &#8211; 8 = 11 &#8211; 5,<br \/>\ntherefore my friend loses 5 fireflies.<\/p>\n<p><strong>Review &amp; Refresh<\/strong><\/p>\n<p>Question 9.<br \/>\ncolor the rectangles.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24997\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-87.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 5 Subtract Numbers within 20 87\" width=\"440\" height=\"88\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-87.png 440w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-87-300x60.png 300w\" sizes=\"(max-width: 440px) 100vw, 440px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-32386\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-49-2.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-49\" width=\"441\" height=\"110\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-49-2.bmp 441w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-49-2-300x75.jpg 300w\" sizes=\"(max-width: 441px) 100vw, 441px\" \/><\/p>\n<p>Explanation:<br \/>\nGiven in the picture we have four shapes and we color the third shape<br \/>\nwhich is rectangle means a quadrilateral with four right angles,\u00a0or a parallelogram<br \/>\ncontaining a right angle, so colored it with purple color.<\/p>\n<p>Question 10.<br \/>\ncolor the squares.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-24996\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-88.png\" alt=\"Big Ideas Math Answers 1st Grade 1 Chapter 5 Subtract Numbers within 20 88\" width=\"412\" height=\"87\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-88.png 412w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-1st-Grade-1-Chapter-5-Subtract-Numbers-within-20-88-300x63.png 300w\" sizes=\"(max-width: 412px) 100vw, 412px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-32385\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-50.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-50\" width=\"444\" height=\"152\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-50.bmp 444w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-50-300x103.jpg 300w\" sizes=\"(max-width: 444px) 100vw, 444px\" \/><br \/>\nExplanation:<br \/>\nGiven in the picture we have four shapes and we color the first shape<br \/>\nwhich is rectangle means a quadrilateral with four right angles,\u00a0or a parallelogram<br \/>\ncontaining a right angle, so colored it with orange color.<\/p>\n<h3><a id=\"Lesson_5.7_Problem_Solving:_Subtraction_within_20\"><\/a>Lesson 5.7 Problem Solving: Subtraction within 20<\/h3>\n<p><strong>Explore and Grow<\/strong><\/p>\n<p>Model the story.<\/p>\n<p>There are 18 seagulls. Some of them fly away. There are 9 left. How many seagulls flew away?<\/p>\n<p>_____9___ seagulls<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-32523\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-51-2.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-51\" width=\"354\" height=\"152\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-51-2.bmp 354w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-51-2-300x129.jpg 300w\" sizes=\"(max-width: 354px) 100vw, 354px\" \/><br \/>\n18 &#8211; 9 = 9<br \/>\n9 seagulls flew away.<\/p>\n<p>Explanation:<br \/>\nGiven there are 18 seagulls. Some of them fly away.<br \/>\nThere are 9 left means out of 18 we are left with 9,<br \/>\nLet us take X number of them fly away means<br \/>\n18 &#8211; X\u00a0 = 9, X = 18 &#8211; 9 = 9, We show in bar model as<br \/>\ntotal we have 18, 9 left and 9 seagulls flew away.<\/p>\n<p><strong>show and Grow<\/strong><\/p>\n<p>Question 1.<br \/>\nYou have some stuffed animals. You give 3 away. You have 8 left. How many stuffed animals did you have to start?<br \/>\nCircle what you know.<br \/>\nUnderline what you need to find.<br \/>\nSolve:<br \/>\n____11____ \u25cb ___3______ = ____8______<\/p>\n<p>_____11_____ stuffed animals<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-32528\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-52-1.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-52\" width=\"234\" height=\"93\" \/><br \/>\n11 &#8211; 3 = 8<br \/>\nI have to start with 11 stuffed animals.<\/p>\n<p>Explanation:<br \/>\nGiven I have some stuffed animals and I give 3 away so have 8 left,<br \/>\nlet I have X number of stuffed animals so From X\u00a0 gave 3 so<br \/>\nX &#8211; 3 = 8 , X = 8 + 3 = 11 I know I gave 3 and left with 8 so I circled them,<br \/>\nI need to know how many stuffed animals I had so underlined it<br \/>\nas shown above in the picture. making equation as 11 &#8211; 3 = 8,<br \/>\ntherefore I have to start with 11 stuffed animals.<\/p>\n<p><strong>Apply and Grow: Practice<\/strong><\/p>\n<p>Question 2.<br \/>\nA group of students are at an arcade. 8 of them leave. There are 3 left. How many students were at the arcade to start?<br \/>\nCircle what you know.<br \/>\nUnderline what you need to find.<br \/>\nSolve:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-25111\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-89.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20 89\" width=\"430\" height=\"135\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-89.png 430w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-89-300x94.png 300w\" sizes=\"(max-width: 430px) 100vw, 430px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-32831\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-53-1.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-53\" width=\"430\" height=\"135\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-53-1.bmp 430w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-53-1-300x94.jpg 300w\" sizes=\"(max-width: 430px) 100vw, 430px\" \/><br \/>\n11 &#8211; 8 = 3,<br \/>\n11 students were at the arcade to start.<\/p>\n<p>Explanation:<br \/>\nGiven a group of students are at an arcade let us take as X,<br \/>\n8 of them leave and there are 3 left means X &#8211; 8 = 3,<br \/>\nX = 3 + 8 = 11 as shown in bar model\u00a0 8 leave and 3 left total 11.<br \/>\nthe equation is 11 &#8211; 8 = 3, I circled 8 and 3 I know, underlined 11<br \/>\nto find. So there are 11 students at the arcade to start.<\/p>\n<p>Question 3.<br \/>\nYou have 15 trucks. Your friend has 7. How many more trucks do you have?<\/p>\n<p>_____8____ more trucks<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-32651\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-54.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-54\" width=\"297\" height=\"148\" \/><br \/>\n15 &#8211; 7 = 8<br \/>\nI have 8 more trucks.<\/p>\n<p>Explanation:<br \/>\nGiven I have 15 trucks and friend have 7, So more trucks I have than my<br \/>\nfriend are 15 &#8211; 7 = 8, as shown in bar model I have 15 and friend have<br \/>\n7 and 8 more trucks I have than my friend.<\/p>\n<p>Question 4.<br \/>\n<strong>DIG DEEPER<\/strong><br \/>\nYou have 16 stickers. Your friend has 7 fewer than you. Which bar model shows how many stickers your friend has?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-25110\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-90.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20 90\" width=\"505\" height=\"133\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-90.png 505w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-90-300x79.png 300w\" sizes=\"(max-width: 505px) 100vw, 505px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-32660\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-55.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-55\" width=\"559\" height=\"197\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-55.bmp 559w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-55-300x106.jpg 300w\" sizes=\"(max-width: 559px) 100vw, 559px\" \/><br \/>\n16 &#8211; 7 = 9<br \/>\ncircled the equation shown in bar model which<br \/>\nshows how many stickers my friend has.<\/p>\n<p>Explanation:<br \/>\nGiven I have 16 stickers and my friend has 7 fewer than me<br \/>\nmeans my friend have 16 &#8211; 7 = 9 stickers ,So I have circled the<br \/>\nequation shown in bar model which shows how many stickers my friend has.<\/p>\n<p><strong>Think and Grow: Modeling Real Life<\/strong><\/p>\n<p>Your friends mask has 13 feathers. Your mask has 7 feathers. How many fewer feathers does your mask have?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-25109\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-91.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20 91\" width=\"114\" height=\"72\" \/><br \/>\nCircle what you know.<br \/>\nUnderline what you need to find.<br \/>\nSolve:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-25108\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-92.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20 92\" width=\"262\" height=\"91\" \/><br \/>\n_________ &#8211; ________ = _________ fewer feathers<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-32805\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-56.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-56\" width=\"481\" height=\"197\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-56.bmp 481w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-56-300x123.jpg 300w\" sizes=\"(max-width: 481px) 100vw, 481px\" \/><br \/>\nExplanation:<br \/>\nGiven friends mask has 13 feathers and my mask has 7 feathers,<br \/>\nSo I have 13 &#8211; 7 = 6 feathers fewer in my mask as shown in the bar model<br \/>\nI have circled 13, 7 in the equation as I know how many my friend<br \/>\nand I have and underlined 6 so that how many fewer feathers my mask have.<\/p>\n<p><strong>Show and Grow<\/strong><\/p>\n<p>Question 5.<br \/>\nThere are 12 party hats. There are 5 fewer noisemakers than party hats. How many noisemakers are there?<br \/>\nCircle what you know.<br \/>\nUnderline what you need to find.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-25107\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-93.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20 93\" width=\"122\" height=\"68\" \/><br \/>\nSolve:<br \/>\n____12_____ &#8211; ____5____ = ____7_____ noisemakers<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-32822\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-57.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-57\" width=\"282\" height=\"100\" \/><br \/>\n12 &#8211; 5 = 7<br \/>\nSo there are 7 noisemakers.<\/p>\n<p>Explanation:<br \/>\nGiven there are 12 party hats and there are 5 fewer<br \/>\nnoisemakers than party hats means 12 &#8211; 5 = 7 noisemakers<br \/>\nare available, as I know how many party hats and how many fewer<br \/>\nnoisemakers are there so I circled them 12, 5 and I need to find how<br \/>\nmany noisemakers are there so I underlined 7 in the equation.<\/p>\n<h3><a id=\"Problem_Solving:_Subtraction_within_20_Practice_5.7\"><\/a>Problem Solving: Subtraction within 20 Practice 5.7<\/h3>\n<p>Question 1.<br \/>\nYou have 12 erasers. Your friend takes some of them. You have 5 left. How many erasers does your friend take?<br \/>\nCircle what you know.<br \/>\nUnderline what you need to find.<br \/>\nSolve:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-25106\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-94.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20 94\" width=\"425\" height=\"130\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-94.png 425w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-94-300x92.png 300w\" sizes=\"(max-width: 425px) 100vw, 425px\" \/><br \/>\nAnswer:<br \/>\n<a href=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-58.bmp\"><img loading=\"lazy\" class=\"alignnone size-full wp-image-32829\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-58.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-58\" width=\"425\" height=\"130\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-58.bmp 425w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-58-300x92.jpg 300w\" sizes=\"(max-width: 425px) 100vw, 425px\" \/><\/a><br \/>\n12 &#8211; 7 = 5<br \/>\nMy friend have taken 7 erasers.<\/p>\n<p>Explanation:<br \/>\nGiven I have 12 erasers and my friend takes some of them<br \/>\nand I have 5 left. Let my friend takes X number so<br \/>\n12 &#8211; X = 5, X = 12 &#8211; 5 = 7 , So 12 &#8211; 7 = 5 as shown in bar model,<br \/>\nAs I know 12 and 5 I have circled it and I need to find<br \/>\nhow many my friend have taken so I have underlined 7 in the<br \/>\nequation.<\/p>\n<p>Question 2.<br \/>\nYou have 17 glitter pens. Your friend has 9 fewer than you. How many does your friend have?<\/p>\n<p>_____8______ glitter pens<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-32833\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-59.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-59\" width=\"299\" height=\"139\" \/><br \/>\n17 &#8211; 9 = 8,<br \/>\nMy friend have 8 glitter pens.<\/p>\n<p>Explanation:<br \/>\nGiven I have 17 glitter pens and my friend has 9 fewer than me,<br \/>\nNow let us take my friend have X number of glitter pens so<br \/>\nX = 17 &#8211; 9, X = 8 therefore my friend have 8 glitter pens.<\/p>\n<p>Question 3.<br \/>\n<strong>DIG DEEPER!<\/strong><br \/>\nA group of students are at a library. 6 of them leave. There are 7 left. Which part-part whole model shows how many students were at the library to start?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-25105\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-95.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20 95\" width=\"231\" height=\"115\" \/><br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-25104\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-96.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20 96\" width=\"366\" height=\"90\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-96.png 366w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-96-300x74.png 300w\" sizes=\"(max-width: 366px) 100vw, 366px\" \/><br \/>\nAnswer:<br \/>\nSecond One <img loading=\"lazy\" class=\"alignnone size-full wp-image-32835\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-60.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-60\" width=\"186\" height=\"109\" \/>shows<br \/>\n13 number students were there at the library to start.<\/p>\n<p>Explanation:<br \/>\nGiven a group of students are at a library 6 of them leave and<br \/>\nthere are 7 left. So a number of students were there at the library<br \/>\nto start are 6 + 7 = 13, so the second one part-part whole model shows<br \/>\nhow many students were there at the library to start.<\/p>\n<p>Question 4.<br \/>\n<strong>Modeling Real Life<\/strong><br \/>\nYour friend\u2019s shirt has 14 buttons. Your shirt has 7 fewer. How many buttons does your shirt have?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-25103\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-97.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20 97\" width=\"83\" height=\"79\" \/><br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-25102\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-98.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20 98\" width=\"247\" height=\"94\" \/><\/p>\n<p>___________ buttons<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-32860\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-61.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-61\" width=\"341\" height=\"141\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-61.bmp 341w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-61-300x124.jpg 300w\" sizes=\"(max-width: 341px) 100vw, 341px\" \/><br \/>\n14 &#8211; 7 = 7<br \/>\nMy shirt have 7 buttons.<\/p>\n<p>Explanation:<br \/>\nGiven my friend\u2019s shirt has 14 buttons and my shirt has 7 fewer,<br \/>\nSo my shirt have 14 &#8211; 7 = 7 buttons as shown in the bar model<br \/>\ntherefore my shirt has 7 buttons.<\/p>\n<p><strong>Review &amp; Refresh<\/strong><\/p>\n<p>Question 5.<br \/>\nThere are 8 <img loading=\"lazy\" class=\"alignnone size-full wp-image-25101\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-99.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20 99\" width=\"35\" height=\"28\" \/>.<br \/>\n3 <img loading=\"lazy\" class=\"alignnone size-full wp-image-25101\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-99.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20 99\" width=\"35\" height=\"28\" \/> swim away.<br \/>\nHow many <img loading=\"lazy\" class=\"alignnone size-full wp-image-25101\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-99.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20 99\" width=\"35\" height=\"28\" \/> are left?<br \/>\n____8____ &#8211; ___3____ = ___5_____ <img loading=\"lazy\" class=\"alignnone size-full wp-image-25101\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-99.png\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20 99\" width=\"35\" height=\"28\" \/><br \/>\nAnswer:<br \/>\n8 &#8211; 3 = 5,<br \/>\nThere are 5 seals left.<\/p>\n<p>Explanation:<br \/>\nGiven there are 8 seals and 3 of them swim away means<br \/>\nfrom 8 we will take 3 making equation as 8 &#8211; 3 = 5,<br \/>\nSo there are 5 seal left.<\/p>\n<h3><a id=\"Chapter_5_Subtract_Numbers_within_20_Performance_Task\"><\/a>Chapter 5 Subtract Numbers within 20 Performance Task<\/h3>\n<p>Question 1.<br \/>\nYou keep track of the number of honeybees and bumblebees you see.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-25551\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-100.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 100\" width=\"533\" height=\"111\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-100.png 533w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-100-300x62.png 300w\" sizes=\"(max-width: 533px) 100vw, 533px\" \/><\/p>\n<p>a. How many more honeybees did you see on Monday than on Tuesday?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-25550\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-101.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 101\" width=\"46\" height=\"41\" \/><\/p>\n<p>_____6_____ more honeybees<br \/>\nAnswer:<\/p>\n<p>12 &#8211; 6 = 6,<br \/>\nI have 6 more honeybees seen on Monday than on Tuesday.<\/p>\n<p>Explanation:<br \/>\nGiven track of the number of honeybees seen<br \/>\nin that on Monday it is 12 and on Tuesday it is 6,<br \/>\nmore number of honeybees seen are 12 &#8211; 6 = 6 on Monday than on Tuesday.<\/p>\n<p>b. How many fewer bees did you see on Monday than on Tuesday?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-25550\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-101.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 101\" width=\"46\" height=\"41\" \/><\/p>\n<p>_____9_____ fewer bees<br \/>\nAnswer:<br \/>\n14 &#8211; 5 = 9<br \/>\n9 fewer bees I have seen on Monday than on Tuesday.<\/p>\n<p>Explanation:<br \/>\nGiven track of the number of bees\u00a0 seen<br \/>\nin that on Monday it is 5 and on Tuesday it is 14, now on Monday<br \/>\nit is less than Tuesday\u00a0 so out of 14 we have seen 5 means<br \/>\nwe have 14 &#8211; 5\u00a0 = 9\u00a0 fewer bees seen on Monday than on Tuesday.<\/p>\n<p>c. How many bumblebees must you see on Wednesday so that the numbers of bees you see on<br \/>\nTuesday and Wednesday are the same?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-25550\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-101.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 101\" width=\"46\" height=\"41\" \/><\/p>\n<p>____14______ bumblebees<br \/>\nAnswer:<br \/>\n14 number of bumblebees I must see on Wednesday so that the numbers<br \/>\nof bees I see on Tuesday and Wednesday are the same.<\/p>\n<p>Explanation:<br \/>\nGiven track of the number of bumblebees seen on Tuesday are 14, So<br \/>\nbumblebees I must\u00a0 see on Wednesday so that the numbers of bees I see on<br \/>\nTuesday and Wednesday are the same are 14 only as both days is should be the same.<\/p>\n<h3><a id=\"Chapter_5_Subtract_Numbers_within_20_Chapter_Practice\"><\/a>Chapter 5 Subtract Numbers within 20 Chapter Practice<\/h3>\n<h3>Count Back to Subtract within 20 Homework &amp; Practice 5.1<\/h3>\n<p>Question 1.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-25549\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-102.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 102\" width=\"424\" height=\"37\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-102.png 424w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-102-300x26.png 300w\" sizes=\"(max-width: 424px) 100vw, 424px\" \/><br \/>\n11 &#8211; 3 = ____8______<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-32868\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-62-1.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-62\" width=\"445\" height=\"139\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-62-1.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-62-1-300x94.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><\/p>\n<p>11 &#8211; 3 = 8<\/p>\n<p>Explanation:<br \/>\nWe subtract 11 &#8211; 3 = 9, on number line we start at 11 and<br \/>\nmove 3 steps back or left we get 8.<\/p>\n<p>Question 2.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-25549\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-102.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 102\" width=\"424\" height=\"37\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-102.png 424w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-102-300x26.png 300w\" sizes=\"(max-width: 424px) 100vw, 424px\" \/><br \/>\n13 &#8211; 4 = _____9_____<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-32867\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-63.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-63\" width=\"445\" height=\"110\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-63.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-63-300x74.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><br \/>\n13 &#8211; 4 = 9<\/p>\n<p>Explanation:<br \/>\nWe subtract 13 &#8211; 4 = 9, on number line we start at 13 and<br \/>\nmove 4 steps back or left we get 9.<\/p>\n<p>Question 3.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-25549\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-102.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 102\" width=\"424\" height=\"37\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-102.png 424w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-102-300x26.png 300w\" sizes=\"(max-width: 424px) 100vw, 424px\" \/><br \/>\n____12______ = 15 &#8211; 3<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-32870\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-64.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-64\" width=\"476\" height=\"110\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-64.bmp 476w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-64-300x69.jpg 300w\" sizes=\"(max-width: 476px) 100vw, 476px\" \/><br \/>\n12 = 15 &#8211; 3<\/p>\n<p>Explanation:<br \/>\nWe subtract 15 &#8211; 3 = 12, on number line we start at 15 and<br \/>\nmove 3 steps back or left we get 12.<\/p>\n<p>Question 4.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-25549\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-102.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 102\" width=\"424\" height=\"37\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-102.png 424w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-102-300x26.png 300w\" sizes=\"(max-width: 424px) 100vw, 424px\" \/><br \/>\n____8______ = 16 &#8211; 8<br \/>\nAnswer:<br \/>\n<a href=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-65-1.bmp\"><img loading=\"lazy\" class=\"alignnone size-full wp-image-32873\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-65-1.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-65\" width=\"445\" height=\"151\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-65-1.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-65-1-300x102.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><\/a><br \/>\n8 = 16 &#8211; 8<\/p>\n<p>Explanation:<br \/>\nWe subtract 16 &#8211; 8 = 8, on number line we start at 16 and<br \/>\nmove 8 steps back or left we get 8.<\/p>\n<h3>Use Addition to Subtract within 20 Homework &amp; Practice 5.2<\/h3>\n<p>Question 5.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-25549\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-102.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 102\" width=\"424\" height=\"37\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-102.png 424w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-102-300x26.png 300w\" sizes=\"(max-width: 424px) 100vw, 424px\" \/><br \/>\n11 &#8211; 9 = ?<br \/>\nThink 9 + ___2____ = 11<br \/>\nSo, 11 &#8211; 9 = ____2_____ .<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-32876\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-66.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-66\" width=\"442\" height=\"234\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-66.bmp 442w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-66-300x159.jpg 300w\" sizes=\"(max-width: 442px) 100vw, 442px\" \/><\/p>\n<p>9 + 2 = 11<br \/>\n11 &#8211; 9 = 2<\/p>\n<p>Explanation:<br \/>\nFirst we move from 9 on number line and start moving till<br \/>\n11 we count how many units right we have moved we get<br \/>\n2 units, so 9 + 2 = 11 or we start at 11 on number line and<br \/>\nmove 9 steps back or left we get 2, 11 &#8211; 9 = 2.<\/p>\n<p>Question 6.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-25549\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-102.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 102\" width=\"424\" height=\"37\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-102.png 424w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-102-300x26.png 300w\" sizes=\"(max-width: 424px) 100vw, 424px\" \/><br \/>\n13 &#8211; 8 = ?<br \/>\nThink 8 + __5_____ = 13<br \/>\nSo, 13 &#8211; 8 = ____5_____ .<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-32878\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-67.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-67\" width=\"451\" height=\"240\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-67.bmp 451w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-67-300x160.jpg 300w\" sizes=\"(max-width: 451px) 100vw, 451px\" \/><br \/>\n8 + 5 = 13<br \/>\n13 &#8211; 8 = 5<\/p>\n<p>Explanation:<br \/>\nFirst we move from 8 on number line and start moving till<br \/>\n13 we count how many units right we have moved we get<br \/>\n5 units, so 8 + 5 = 13 or we start at 13 on number line and<br \/>\nmove 8 steps back or left we get 5 so 13 &#8211; 8 = 5.<\/p>\n<p>Question 7.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-25549\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-102.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 102\" width=\"424\" height=\"37\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-102.png 424w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-102-300x26.png 300w\" sizes=\"(max-width: 424px) 100vw, 424px\" \/><br \/>\n____13_____ = 20 &#8211; 7<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-32883\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-68.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-68\" width=\"451\" height=\"240\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-68.bmp 451w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-68-300x160.jpg 300w\" sizes=\"(max-width: 451px) 100vw, 451px\" \/><br \/>\n13 + 7 = 20<br \/>\n20 &#8211; 7 = 13<\/p>\n<p>Explanation:<br \/>\nFirst we move from 13 on number line and start moving till<br \/>\n20 we count how many units right we have moved we get<br \/>\n7 units, so 13 + 7 = 20 or we start at 20 on number line and<br \/>\nmove 7 steps back or left we get 13 so 20 &#8211; 7 = 13.<\/p>\n<p>Question 8.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-25549\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-102.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 102\" width=\"424\" height=\"37\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-102.png 424w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-102-300x26.png 300w\" sizes=\"(max-width: 424px) 100vw, 424px\" \/><br \/>\n____9____ = 12 &#8211; 3<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-32887\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-69.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-69\" width=\"451\" height=\"227\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-69.bmp 451w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-69-300x151.jpg 300w\" sizes=\"(max-width: 451px) 100vw, 451px\" \/><br \/>\n9 + 3 = 12<br \/>\n9 = 12 &#8211; 3<\/p>\n<p>Explanation:<br \/>\nFirst we move from 9 on number line and start moving till<br \/>\n12 we count how many units right we have moved we get<br \/>\n3 units so 9 + 3 = 12 or we start at 12 on number line and<br \/>\nmove 3 steps back or left we get 9 so 12 &#8211; 3 = 9.<\/p>\n<h3>Subtract 9 Homework &amp; Practice 5.3<\/h3>\n<p>Get to 10 to subtract<\/p>\n<p>Question 9.<br \/>\n15 &#8211; 9 = ?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-25548\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-103.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 103\" width=\"124\" height=\"114\" \/><br \/>\n15 &#8211; ____5____ = 10<br \/>\n10 &#8211; _____4_____ = ____6_____<br \/>\nSo, 15 &#8211; 9 = ___6_____<br \/>\nAnswer:<br \/>\n15 &#8211; 5 = 10<br \/>\n10 &#8211; 4 = 6<br \/>\nSo, 15 &#8211; 9 = 6<\/p>\n<p>Explanation:<br \/>\nWe have 2 counters in counter one we have 10 circles<br \/>\nand in the next counter we have 5 circles so in total we have 15,<br \/>\nFirst we see out of 15 if we consider counter-2 we have 5 strike outs<br \/>\nmeans 15 &#8211; 5 = 10 we got 10 in counter-1 and if we see first counter<br \/>\nwe have 4 strike outs 10 &#8211; 4 = 6, So total number of circles strike out<br \/>\nfrom 2-counters are 5 + 4 = 9, So making equation as 15 &#8211; 9 = 6.<\/p>\n<p>Question 10.<br \/>\n17 &#8211; 9 =?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-25547\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-104.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 104\" width=\"125\" height=\"112\" \/><br \/>\n17 &#8211; ___7_____ = 10<br \/>\n10 &#8211; _____2_____ = ____8_____<br \/>\nSo, 17 &#8211; 9 = ____8____<br \/>\nAnswer:<br \/>\n17 &#8211; 7 = 10<br \/>\n10 &#8211; 2 = 8<br \/>\nSo, 17 &#8211; 9 = 8<\/p>\n<p>Explanation:<br \/>\nWe have 2 counters in counter one we have 10 circles<br \/>\nand in next counter we have 7 circles so in total we have 17,<br \/>\nFirst we see out of 17 if we consider counter-2 we have 7 strike outs<br \/>\nmeans 17 &#8211; 7 = 10 we got 10 in counter-1 and if we see first counter<br \/>\nwe have 2 strike outs 10 &#8211; 2 = 8, So total number of circles strike out<br \/>\nfrom 2-counters are 7 + 2 = 9, So making equation as 17 &#8211; 9 = 8.<\/p>\n<h3>Get to 10 to subtract Homework &amp; Practice 5.4<\/h3>\n<p>Get to 10 to subtract<\/p>\n<p>Question 11.<br \/>\n12 &#8211; 7 = ?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-25546\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-105.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 105\" width=\"124\" height=\"112\" \/><br \/>\n12 &#8211; ____2_____ = 10<br \/>\n10 &#8211; ____5______ = ____5_____<br \/>\nSo, 12 &#8211; 7 = _____5_____ .<br \/>\nAnswer:<br \/>\n12 &#8211; 2 = 10<br \/>\n10 &#8211; 5 = 5<br \/>\nSo, 12 &#8211; 7 = 5.<\/p>\n<p>Explanation:<br \/>\nWe have 2 counters in counter one we have 10 circles<br \/>\nand in the next counter, we have 2 circles so in total we have 12,<br \/>\nFirst, we see out of 12 if we consider counter-2 we have 2 strike outs<br \/>\nmeans 12 &#8211; 2 = 10 we got 10 in counter-1 and if we see first counter<br \/>\nwe have 5 strike outs 10 &#8211; 5 = 5, So the total number of circles strike out<br \/>\nfrom 2-counters are 5 + 2 = 7, So making equation as 12 &#8211; 7 = 5.<\/p>\n<p>Question 12.<br \/>\n17 &#8211; 8 = ?<br \/>\n17 &#8211; ____7____ = 10<br \/>\n10 &#8211; ____1_____ = ___9_____<br \/>\nSo, 17 &#8211; 8 = ___9____ .<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-32890\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-70.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-70\" width=\"162\" height=\"131\" \/><br \/>\n17 &#8211; 7 = 10<br \/>\n10 &#8211; 1 = 9<br \/>\nSo, 17 &#8211; 8 = 9<\/p>\n<p>Explanation:<br \/>\nWe have 2 counters in counter one we have 10 circles<br \/>\nand in the next counter, we have 7 circles so in total we have 17,<br \/>\nFirst, we see out of 17 if we consider counter-2 we have 7 strike outs<br \/>\nmeans 17 &#8211; 7 = 10 we got 10 in counter-1 and if we see the first counter<br \/>\nwe have 1 strike outs 10 &#8211; 1 = 9, So the total number of circles strike out<br \/>\nfrom 2-counters are 7+ 1 = 8, So making equation as 17 &#8211; 8 = 9.<\/p>\n<h3>More True or False Equations Homework &amp; Practice 5.5<\/h3>\n<p>Is the equation true or false?<\/p>\n<p>Question 13.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-25545\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-106.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 106\" width=\"434\" height=\"124\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-106.png 434w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-106-300x86.png 300w\" sizes=\"(max-width: 434px) 100vw, 434px\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-32893\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-71-1.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-71\" width=\"473\" height=\"131\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-71-1.bmp 473w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-71-1-300x83.jpg 300w\" sizes=\"(max-width: 473px) 100vw, 473px\" \/><\/p>\n<p>8 + 3 + 8\u00a0 = 13 + 6<br \/>\n19 = 19 ,<br \/>\nSo True.<\/p>\n<p>Explanation:<br \/>\nWe take 8 + 3 + 8 means adding 8 to 3 and<br \/>\nagain adding 8 we get 8 + 3 + 8 = 19<br \/>\nNow 13 + 6 is 19 so both sides are equal therefore<br \/>\n8 + 3 +8 = 13 + 6 is True.<\/p>\n<p>Question 14.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-25544\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-107.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 107\" width=\"146\" height=\"122\" \/><br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-32894\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-72.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-72\" width=\"207\" height=\"135\" \/><br \/>\n16 &#8211; 8 = 6 + 2<br \/>\n8 = 8<br \/>\nSo True.<\/p>\n<p>Explanation:<br \/>\nWe take 16 &#8211; 8 means subtracting 8 from 16<br \/>\nwe get 16 &#8211; 8 = 8,<br \/>\nNow 6 + 2 is 8 so both sides are equal therefore<br \/>\n16 &#8211; 6\u00a0 = 6 + 2\u00a0 is True.<\/p>\n<p>Question 15.<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-25543\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-108.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 108\" width=\"161\" height=\"121\" \/><br \/>\nAnswer:<br \/>\n<a href=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-73.bmp\"><img loading=\"lazy\" class=\"alignnone size-full wp-image-32895\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-73.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-73\" width=\"207\" height=\"135\" \/><\/a><\/p>\n<p>14 &#8211; 7 = 7 \u2260 12 &#8211; 9 = 3<br \/>\n7 \u2260 3<br \/>\nSo False<\/p>\n<p>Explanation:<br \/>\nWe take 14 &#8211; 7 means subtracting 7 from 14 we get 14 &#8211; 7 = 7<br \/>\nand 12 -9 means subtracting\u00a0 9 from 12 we get 12 &#8211; 9 = 3,<br \/>\nIf we see both sides they are not equal as 7 \u2260 3,<br \/>\nSo 14 &#8211; 7 = 12 -9 is False.<\/p>\n<h3>Make True Equations Homework &amp; Practice 5.6<\/h3>\n<p>Question 16.<br \/>\n11 &#8211; 7 = 10 &#8211; ?<br \/>\n___4____ = 10 &#8211; ?<br \/>\n___4____ = 10 &#8211; ___6_____<br \/>\nSo, 11 &#8211; 7 = 10 &#8211; ___6_____ .<br \/>\nAnswer:<\/p>\n<p>11 &#8211; 7 = 10 &#8211; ____<br \/>\n___4____ = 10 &#8211; ___<br \/>\n___4____ = 10 &#8211; ___6_____<br \/>\nSo, 11 &#8211; 7 = 10 &#8211; ___6_____ .<\/p>\n<p>Explanation :<br \/>\nGiven 11 &#8211; 7 = 10 &#8211;\u00a0 ___, First we see 11 &#8211; 7 = 4 means<br \/>\n10 &#8211; ___ = 4 So let us take missing number as X ,<br \/>\n10 &#8211; X = 4 therefore X = 10 &#8211; 4 = 6 making true equation as<br \/>\n11 &#8211; 7 = 10 &#8211; 6.<\/p>\n<p>Question 17.<br \/>\n2 + 0 + 6 = ? &#8211; 5<br \/>\n____8____ = ? &#8211; 5<br \/>\n____8____ = ___13___ &#8211; 5<br \/>\nSo, 2 + 0 + 6 = ____13____ &#8211; 5<br \/>\nAnswer:<br \/>\n2 + 0 + 6 = ____ &#8211; 5<br \/>\n____8____ = ___ &#8211; 5<br \/>\n____8____ = ___13___ &#8211; 5<br \/>\nSo, 2 + 0 + 6 = ____13____ &#8211; 5<\/p>\n<p>Explanation :<br \/>\nGiven 2 + 0 + 6 = ___- 5 , First we see 2 + 0 + 6 = 8 means<br \/>\n___ &#8211; 5 = 8 So let us take missing number as X ,<br \/>\nX &#8211; 5 = 8 therefore X = 8 + 5 = 13 making true equation as<br \/>\n2 + 0 + 6 = 13 &#8211; 5.<\/p>\n<h3>Problem Solving: Subtraction within 20 Homework &amp; Practice 5.7<\/h3>\n<p>Question 18.<br \/>\nThere are 13 people on a train. Some of them exit. There are 5 left. How many people exit the train?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-25542\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-109.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 109\" width=\"173\" height=\"148\" \/><br \/>\nCircle what you know.<br \/>\nUnderline what you need to find.<br \/>\nSolve:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-25541\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-110.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 110\" width=\"422\" height=\"40\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-110.png 422w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-110-300x28.png 300w\" sizes=\"(max-width: 422px) 100vw, 422px\" \/><\/p>\n<p>_____13_____ \u25cb- ____8______ = _____5______, ____8_____ people<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33040\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-74.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-74\" width=\"445\" height=\"171\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-74.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-74-300x115.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><br \/>\n13 &#8211; 8 = 5<br \/>\n8 people exit the train.<\/p>\n<p>Explanation:<br \/>\nGiven there are 13 people on a train, some of them exit and<br \/>\nthere are 5 left. On number line we start at 13 and move 5 units<br \/>\nleft or back so we reach at 8 means 8 people exit the train,<br \/>\nAs we know 13 people are on the train and 5 left we circle<br \/>\nin the equation and we need to know how many exit the train,<br \/>\nso we underline 8 in the equation\u00a0 13 &#8211; 8 =5 above.<\/p>\n<p>Question 19.<br \/>\nA group of students are at a museum. 8 of them leave. There are 7 left. How many students were there to start ?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-25540\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-111.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 111\" width=\"119\" height=\"80\" \/><\/p>\n<p>_____15_______ Students<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33068\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-75.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-75\" width=\"445\" height=\"143\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-75.bmp 445w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-75-300x96.jpg 300w\" sizes=\"(max-width: 445px) 100vw, 445px\" \/><br \/>\n8 + 7 = 15 or 15 &#8211; 8 = 7<br \/>\nThere were 15 students at the start.<\/p>\n<p>Explanation:<br \/>\nGiven a group of students are at a museum, 8 of them leave,<br \/>\nThere are 7 left. We start from 8 and move 7 units rights we get 15,<br \/>\n8 + 7 = 15, So there are 15 students at the start.<\/p>\n<p>Question 20.<br \/>\nYou and a friend play basketball. Your friend scores 17 points. You score 8 fewer. How many points do you score?<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-25539\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Solutions-Grade-1-Chapter-5-Subtract-Numbers-within-20-112.png\" alt=\"Big Ideas Math Solutions Grade 1 Chapter 5 Subtract Numbers within 20 112\" width=\"59\" height=\"56\" \/><\/p>\n<p>_____9_______ points<br \/>\nAnswer:<br \/>\n<img loading=\"lazy\" class=\"alignnone size-full wp-image-33069\" src=\"https:\/\/ccssmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-76.bmp\" alt=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20-76\" width=\"439\" height=\"142\" srcset=\"https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-76.bmp 439w, https:\/\/bigideasmathanswers.com\/wp-content\/uploads\/2021\/01\/Big-Ideas-Math-Answers-Grade-1-Chapter-5-Subtract-Numbers-within-20-76-300x97.jpg 300w\" sizes=\"(max-width: 439px) 100vw, 439px\" \/><br \/>\n17 &#8211; 8 = 9<br \/>\nI scored 9 points.<\/p>\n<p>Explanation:<br \/>\nGiven I and a friend play basketball my friend scores 17 points<br \/>\nand I score 8 fewer. On the number line, I start from 17 and move<br \/>\n8 steps left I reach at 9 means 17 &#8211; 8 = 9, so I scored 9 points.<\/p>\n<p><em>Conclusion:<\/em><\/p>\n<p>Students can find Big Ideas Math Solution Keys for all the chapters at one place. All the Concepts in the Big Ideas Math Answer are prepared by the subject experts. Resolve all your queries and assess your preparation standard using the Common Core Big Ideas Math Grade 1 Answer Key.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Enhance your subject knowledge by taking the help of the Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20. Practice Big Ideas Math Book 1st Grade Answer Key Chapter 5 Subtract Numbers within 20 and answer the questions from the chapter with confidence. The detailed explanation provided helps you understand the topics &#8230; <a title=\"Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20\" class=\"read-more\" href=\"https:\/\/bigideasmathanswers.com\/big-ideas-math-answers-grade-1-chapter-5\/\" aria-label=\"More on Big Ideas Math Answers Grade 1 Chapter 5 Subtract Numbers within 20\">Read more<\/a><\/p>\n","protected":false},"author":8,"featured_media":89527,"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-5.png","_links":{"self":[{"href":"https:\/\/bigideasmathanswers.com\/wp-json\/wp\/v2\/posts\/24645"}],"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\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/bigideasmathanswers.com\/wp-json\/wp\/v2\/comments?post=24645"}],"version-history":[{"count":1,"href":"https:\/\/bigideasmathanswers.com\/wp-json\/wp\/v2\/posts\/24645\/revisions"}],"predecessor-version":[{"id":90323,"href":"https:\/\/bigideasmathanswers.com\/wp-json\/wp\/v2\/posts\/24645\/revisions\/90323"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/bigideasmathanswers.com\/wp-json\/wp\/v2\/media\/89527"}],"wp:attachment":[{"href":"https:\/\/bigideasmathanswers.com\/wp-json\/wp\/v2\/media?parent=24645"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/bigideasmathanswers.com\/wp-json\/wp\/v2\/categories?post=24645"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/bigideasmathanswers.com\/wp-json\/wp\/v2\/tags?post=24645"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}