Spots Book Grade 2 - Volume I

Spots for M.A.T.H. Second Grade Mathbook Student Edition Volume lCopyright © 2017 by Nechemia & Sarah G. Weiss, Spots Educational Resources. All Rights Reserved. Published in the United States by Spots Educational Resources, Brooklyn, N.Y. Program Authors:Nechemia Weiss, M.S. Ed., SpEd., Childhood Education Teacher, (Grades 1-6), Brooklyn, N.Y. Sarah G. Weiss, Math Specialist, Brooklyn, N.Y. Senior Reviewer:Brenda Strassfeld, Ph.D. Chair of Mathematics Education Program, Graduate School of Education, Touro College, New York, N.Y. Consulting Reviewers:Basi Blumberg, M.S., Ed. Math Curriculum Specialist, Queens ,N.Y.Sara C. Mizrahi, B.A. Teacher Reviewers: Teacher’s Certification, Yavne Teachers’ College, Cleveland, OH.Editorial and Design Services: Summer Street Content, LLC. Westport, CT. Art Design : William McAllisterArt Credits: © Art Explosion® 800,000 Clip Art by Nova Development / Royalty-Free Š ShutterstockCommon Core State Standards for Mathematics: corestandards.org © Copyright 2010 National GovernorsAssociation Center for Best Practices and Council of Chief State School Officers. All rights reserved.This product is not sponsored or endorsed by the Common Core State Standards for Mathematics initiativeof the National Governors Association Center for Best Practices (NGA Center) and the Council of Chief StateSchool Officers (CCSSO).Special thanks to the many teachers, students, parents, principals, writers and work-study students whoparticipated in the Spots for MATH project development over the years.This publication, or parts thereof, may not be reproduced in any form by photographic, electrostatic,mechanical, or any other method, for any use, including information storage and retrieval, without writtenpermission from the publisher.Spots for Mathematical Abilities & Thinking Habits is a registered trademark of Spots Educational Resources.Dot Cards included herein are protected with the following United States Patents. D621,878 S as a Mathemati-cal Educational Set, and D757,175 S as a Educational Set of Cards for Addition and Subtraction.Publisher: Spots Educational Resources 5314 16th Avenue, Unit 101, Brooklyn, NY 11204Phone: (718) 306-9898 Š Fax: (718) 350-8876 Š Email: [email protected] Š www.spotsmath.comISBN: 978-0-9851129-5-01 2 3 4 5 6 7 8 20 19 18 17Printed in the U.S.A

Chapter1 Addition and Subtraction Through Teen NumbersChapter 1 Opener ....................................................................................................................1Lesson 1 Addition Through Ten ...................................................................................... ..3Lesson 2 Practice: Addition Through Ten ........................................................................ 5Lesson 3 Subtraction Through Ten ................................................................................... 7Lesson 4 Practice: Subtraction Through Ten................................................................... 9Lesson 5 Number Families ...............................................................................................11Lesson 6 Problem Solving: Both Addends Unknown ................................................13Lesson 7 Finding the Unknown Number.......................................................................15Lesson 8 Problem Solving: Finding the Unknown Number in Story Problems .....17Lesson 9 Adding to Teen Numbers.................................................................................19Lesson 10 Adding in Two Steps .........................................................................................21Lesson 11 Practice: Addition with Teen Sums ................................................................23Lesson 12 Using the Number Line to Add .......................................................................25Lesson 13 Choosing a Way to Add ...................................................................................27Lesson 14 Adding with Three Addends ...........................................................................29Lesson 15 Subtracting from Teen Numbers....................................................................31Lesson 16 Subtracting in Two Steps .................................................................................33Lesson 17 Practice: Subtracting in Two Step ..................................................................35Lesson 18 Using the Number Line to Subtract...............................................................37Lesson 19 Choosing a Way to Subtract ............................................................................39Lesson 20 Subtracting a Lot from a Teen Number.........................................................41Lesson 21 Mixed Practice: Teen Subtraction...................................................................43Lesson 21 End-of-Chapter Review....................................................................................43 i

Chapter2 Two-Digit NumbersChapter 2 Opener ................................................................................................................. 47Lesson 1 Representing Two-Digit Numbers ................................................................49Lesson 2 Place Value..........................................................................................................51Lesson 3 Expanded Form .................................................................................................53Lesson 4 Comparing Numbers ........................................................................................55Lesson 5 Counting by Five ...............................................................................................57Lesson 6 Quarters ..............................................................................................................59Lesson 7 Ten More, Ten Less ............................................................................................61Lesson 8 Counting On by Ten ..........................................................................................63Lesson 9 Counting a Collection of Coins .......................................................................65Lesson 10 Making Equal Collections of Coins ................................................................67Lesson 11 Odd and Even.....................................................................................................69Lesson 12 End-of-Chapter Review....................................................................................71ii

XxxChapter3 Addition with Two-Digit NumbersChapter 3 Opener ................................................................................................................. 73Lesson 1 Adding Ones to Two-Digit Numbers ............................................................ 75Lesson 2 Adding to the Next Ten ....................................................................................77Lesson 3 Number Line: Adding to the Next Ten...........................................................79Lesson 4 Finding the Missing Addend...........................................................................81Lesson 5 Adding Three Addends .................................................................................... 83Lesson 6 Adding Ones with Regrouping.......................................................................85Lesson 7 Practice: Adding Ones with Regrouping ......................................................87Lesson 8 Number Line: Regrouping Ones.....................................................................89Lesson 9 Number Line: Adding 10 to a Two-Digit Number .......................................91Lesson 10 Number Line: Adding Decade Numbers to Two-Digit Numbers..............93Lesson 11 Adding Only Tens vs. Adding Only Ones .....................................................95Lesson 12 Number Line: Adding 2 Two-Digit Numbers................................................97Lesson 13 Problem Solving: Two-Step Story Problems ................................................99Lesson 14 Number Line: Adding to the Next Ten (Two-Digit Addends)..................101Lesson 15 Practice: Adding to the Next Ten..................................................................103Lesson 16 Number Line: Adding with Three Jumps ....................................................105Lesson 17 Practice: Adding with Three Jumps .............................................................107Lesson 18 Number Line: Drawing Two or Three Jumps ..............................................109Lesson 19 Adding in Columns with Regrouping..........................................................111Lesson 20 A Practice: Adding in Columns .....................................................................113Lesson 21 Choosing a Strategy to Add ..........................................................................115Lesson 22 Adding with Three Addends .........................................................................117Lesson 23 Problem Solving: Two-Step Story Problems ..............................................119Lesson 24 End-of-Chapter Review..................................................................................121 iii

Chapter4 Subtraction with Two-Digit NumbersChapter 4 Opener ...............................................................................................................123Lesson 1 Subtracting Ones from a Two-Digit Number ........................................... 125Lesson 2 Subtracting Tens from a Two-Digit Number ..............................................127Lesson 3 Problem Solving: Two-Step Story Problems, Subtracting Twice ............129Lesson 4 Subtracting Two-Digit Numbers ..................................................................131Lesson 5 Regrouping with Dot Cards...........................................................................133Lesson 6 Practice: Regrouping with Dot Cards ..........................................................135Lesson 7 Regrouping in Columns ................................................................................137Lesson 8 Problem Solving: Two-Step Story Problems, Adding and Subtracting ...139Lesson 9 Mixed Practice: Subtracting in Columns.....................................................141Lesson 10 Number Line: Subtracting Ones from a Decade Number .......................143Lesson 11 Number Line: Subtracting Ones from a Two-Digit Number ...................145Lesson 12 Number Line: Practice: Subtracting Ones from a Two-Digit Number ...147Lesson 13 Choosing a Strategy .......................................................................................149Lesson 14 Problem Solving: Story Problems with Change Unknown ......................151Lesson 15Lesson 16 Problem Solving: Story Problems with Start Unknown........................ 153Lesson 17 Practice: Problem Solving: Mixed Story Problems .................................155Lesson 18 End-of-Chapter Review ..........................................................................157 Cumulative Review ...............................................................................159iv

XxxCHAPTER 1Addition and SubtractionThrough Teen Numbers 1

Xxx.2

Fill in the addition number sentence. Addition Through Ten 1. 2. 3. == =Add. Circle the doubles facts. 8. 7 +24. 6 5. 7 6. 4 7. 5 +2 +3 +2 +49. 5 10. 3 11. 6 12. 4 13. 6 +5 +3 +4 +3 +314. 4 15. 7 16. 5 17. 2 18. 9 +4 +0 +3 +2 +1Chapter 1 Lesson 1 OA.2 Addition Through Ten 3

Write the number sentence and solve. 1. Tamara has 5 fuzzy stickers. She gets 2 shiny stickers as a reward. How many stickers does she have in all?Number sentence:Tamara has stickers in all.2. For snack, Benny has 6 slices of apple and 3 slices of banana. How many slices of fruit does Benny have? Number sentence: Benny has slices of fruit.3. 8 cats sit near a tree. 2 more cats come to sit there. How many cats are near the tree? Number sentence: There are cats near the tree.4. Mike has 4 goldfish. Bill has 3 more goldfish than Mike. How many goldfish does Bill have?Number sentence: Bill has goldfish.4

Practice: Addition Through TenDraw a line to the crayon that shows When we add, we think ofthe matching number sentence. the greater number first!Fill in the sums.1. 3 + 7 = 6+2=2. 2 + 6 = 5+3=3. 3 + 4 = 7+3= 4. 3 + 5 = 4+3= Add. 8. 4 + 5 = 5. 1 + 4 = 9. 3 + 5 = 6. 2 + 4 = 7. 3 + 4 = 10. 1 + 5 =11. 4 + 6 = 14. 2 + 7 =12. 2 + 6 =13. 3 + 6 = 15. 3 + 7 =Chapter 1 Lesson 2 16. 1+7= 5 OA.2 Practice: Addition Through Ten

There are different ways to make a sum of ten.Fill in the missing addend to complete the number sentence. 1. 8 + = 10 2. 5 + = 10 3. 7 + = 10 4. 10 + = 10 5. 6 + = 10 6. 9 + = 10Add. Think of the greater addend first. 7. 3 + 5 = 8. 2 + 4 = 9. 4 + 5 =10. 0 + 7 = 11. 6 + 3 = 12. 3 + 7 =13. 3 + 4 = 14. 1 + 6 = 15. 2 + 5 =16. 6 + 4 = 17. 2 + 7 = 18. 2 + 6 =LET’S WRITE!How does knowing how to solve 7 + 3 help you solve 3 + 7?6

When we subtract a little, Subtraction Through Ten we cross off the dots from the top as we count back. 10 – 2 = 8We cross off the 10 and 9.There are 8 left.Cross off the dots you need to subtract. 4.Write the difference.1. 2. 3. 6–2= 9–3= 9–4= 8–3=5. 6. 7. 8.5–2= 10 – 3 = 10 – 4 = 7–2=Subtract. 10. 11. 12. 9. 6–1= 7–3= 9–2= 10 – 2 =13. 14. 15. 16. 5–1= 8–2= 4–0= 7–1=Chapter 1 Lesson 3 OA.2 Subtraction Through Ten 7

When we subtract a lot, we cross off 10 – 7 = 3 the dots from the bottom and count 4. on to see how much is left.We cross off 7. We are left with 8, 9, and 10.There are 3 left.Cross off the dots you need to subtract.Write the difference. 1. 2. 3.9–7= 10 – 6 = 6–5= 8–6=5. 6. 7. 8. 7–4= 9–5= 9–6= 10 – 9 =Subtract. 10. 11. 12. 9. 8–7= 6–4= 9–8= 10 – 5 = 14. 15. 16.13. 4–3= 10 – 8 = 8–4= 5–5=8

Practice: Subtraction Through TenDecide if you are subtracting a lot or a little. 4.Cross off the dots you need to subtract.Write the difference. 1. 2. 3. 9–7= 9–3= 8–2= 8–5=5. 6. 7. 8.10 – 4 = 10 – 8 = 8–7= 8–3=9. 10. 11. 12. 9–6= 9–4= 7–6= 7–2=13. 14. 15. 16.8–1= 8–6= 5–4= 5–2=Chapter 1 Lesson 4 OA.2 Practice: Subtraction Through Ten 9

Subtract. 2. 7 3. 6 4. 9 5. 10 6. 4 –5 –2 –8 –3 –0 1. 10 –67. 5 8. 9 9. 6 10. 8 11. 7 12. 4 –4 –3 –3 –5 –3 –213. 10 14. 8 15. 7 16. 6 17. 9 18. 8 –5 –4 –4 –6 – 5 –6Write the number sentence and solve.19. Nan has 10 markers. Lizzy has 3 fewer markers than Nan. How many markers does Lizzy have? Number sentence: Lizzy has markers. LET’S WRITE! Look at exercise number 18. Explain how you solved 8 – 6.10

Number FamiliesThe Numbers in a Math Puzzle Are a Family When we add, we begin with a part. When we subtract, we begin with the whole.Complete each math puzzle.Write four number sentences for each math puzzle.1. 2. Whole Whole Part Part Part Part += += Part Part Whole Part Part Whole += += Part Part Whole Part Part Whole –= –= Whole Part Part Whole Part Part –= –= Whole Part Part Whole Part Part3. 4. Whole Whole Part Part Part Part += += Part Part Whole Part Part Whole += += Part Part Whole Part Part Whole –= –= Whole Part Part Whole Part Part –= –= Whole Part Part Whole Part PartChapter 1 Lesson 5 OA.2 Number Families 11

Write two number sentences for each math puzzle.1. 2 4 6 2. 6 8 2 3. 9 4 5 Whole Whole Whole Part Part Part Part Part Part += += += Part Part Whole Part Part Whole Part Part Whole –= Part –= –= Whole Part Whole Part Part Whole Part Part4. 8 3 5 5. 4 10 6 6. 5 2 3 Whole Whole Whole Part Part Part Part Part Part += += += Part Part Whole Part Part Whole Part Part Whole –= –= –= Whole Part Part Whole Part Part Whole Part Part LET’S WRITE! Look at number 6. How did you decide which number was the whole and which numbers were the parts?12

Problem Solving: Both Addends UnknownCircle the number sentence that shows the correct addends.Complete the math puzzle.1. Brian has 10 marbles. 10 Some are red and some are blue. Whole10 = 6 + 4 10 = 6 + 3 Part Part2. Megan has 7 rocks. 7 Some are big and some are small. Whole7=3+3 7=4+3 Part Part3. Tami has 6 pens. 6 Some are blue and some are black. Whole6=4+2 6=5+2 Part Part4. A store sold 9 stuffed animals. 9 Some are bears and some are lions. Whole9=7+2 9=7+3 Part PartChapter 1 Lesson 6 OA.1 Problem Solving: Both Addends Unknown 13

Write more than one possible pair of addends. WholeFill in the math puzzles for each story problem. 1. Melissa has 8 pieces of fruit. Some are grapes and some are cherries. 8 Whole Part Part Part Part8= + 8= +2. John has 5 apples. 5 Some are red and some are green. Whole 5 Whole Part Part Part Part5= + 5= +3. Hong took 7 photos yesterday. Some are of family and some are of friends. In what ways, could Hong have split the photos? 7 7 7 Whole Whole Whole Part Part Part Part Part Part 7= + 7= + 7= +14

Finding the Unknown NumberWe can use a to represent the unknown number. When we know both parts, When we know the whole andwe add them together to find one part we subtract to find the whole. the other part. Whole 8 35 Whole Part Part 3 = Part Part Part Part Whole Whole = Part PartWrite the number sentence to find the unknown number.1. 2. 3. 7 Whole 9 Whole 64 Whole 4 Part Part 2 Part Part Part PartWhole = Part = Whole = Part Part Part Whole Part PartChapter 1 Lesson 7 OA.2 Finding the Number 15

Write the number sentence to find the unknown number.1. 2. 3. 10 Whole 8 Whole 25 Whole 7 Part Part 4 Part Part Part PartWhole = Part = Whole =4. Part Part 5. Part Whole 6. Part Part 9 6 Whole Whole Whole 46 3 1 Part Part Part Part Part PartWhole = Whole = Part =7. Part Part 8. Part Part 9. Part Whole Whole 6 8 45 Whole Whole Part Part 4 6 Part Part Part Part == =Part Part Whole Whole Part Part Whole Part Part16

Finding the Unknown Number in Story ProblemsElla has 9 T-shirts. We can use a to5 T-shirts are colored. The rest are white. represent the unknownHow many T-shirts are white? number. –= WholeWhole Part Part Part Part –=Whole Part PartT-shirts are white..Write the number sentence and fill in the math puzzle.Use a for the unknown number. Solve. Whole Part Part 1. Natalie has 10 postcards. 7 postcards are from her grandparents. The rest are from her aunt. How many postcards are from Natalie’s aunt? Number sentence:Natalie has ______ postcards from her aunt.2. Jeremy has 8 pink balloons Whole and 2 blue balloons. Part Part How many balloons does Jeremy have in all? Number sentence: Jeremy has _______ balloons in all.Chapter 1 Lesson 8 OA.1 Finding the Unknown Number in Story Problems 17

Fill in the math puzzle and write the number sentence.Use a for the unknown number. Solve.1. There are 9 birds in a tree. Whole 4 of the birds are blue. How many of the birds are a different color?Number sentence: Part Part of the birds are a different color. Whole2. Kevin has 5 books in a box. 3 books are hardcover. The rest are paperback. How many paperback books are in the box?Number sentence: Part PartKevin has paperback books in the box.3. Carmella has 3 shiny stickers Whole and 6 fuzzy stickers. How many stickers does she have in all?Number sentence: Part PartShe has stickers in all. Whole Part Part4. Rosa listened to 8 songs. She liked 5 of the songs. The rest she did not like. How many of the songs did Rosa not like? Number sentence: of the songs. Rosa did not like18

Adding to Teen NumbersAdd.1. 2. 3. 4. 5. 6. 1 11 4 14 2 12 +5 +5 +3 +3 +7 +77. 8. 9. 10. 11. 12. 3 13 1 11 3 13 +5 +5 +6 +6 +3 +3Write the number sentence that will help solvethe exercise. Solve.13. 14. 12 + 6 = 15 + 4 = += +=15. 16. 11 + 7 = 13 + 6 = += +=17. 18. 12 + 5 = 14 + 4 = += +=Chapter 1 Lesson 9 OA.2 Adding to Teen Numbers 19

Add.1. 2. 3. 4. 14 + 3 = ___ 10 + 6 = ___ 15 + 4 =___ 17 + 2 =___5. 6. 7. 8. 13 + 5 = ___ 12 + 4 = ___ 11 + 8 = ___ 12 + 6 = ___9. 10. 11. 12. 10 + 9 = ___ 13 + 4 = ___ 14 + 5 = ___ 16 + 3 = ___13. 14. 15. 16. 12 + 2 = ___ 11 + 4 = ___ 13 + 6 = ___ 14 + 4 = ___Fill in the math puzzle and write the number sentence. WholeUse a for the unknown number. Solve.17. Rafael has 10 carrot sticks. He has 5 celery sticks. How many vegetable sticks does Rafael have?Number sentence: Part Part WholeRafael has vegetable sticks.18. Kelli has 10 bananas. She buys 4 oranges. How many pieces of fruit does Kelli have? Number sentence: Part Part Kelli has _______ pieces of fruit.20

Adding in Two Steps When the sum will be more than 10, we add in two steps: First we add to make a ten. Then we add the rest to the ten to get the sum.8 + 6 = 14 We break apart the 6.24 2 and 4 are the break-apart numbers.to make ten the rest Color the dots and draw an arrow to make a ten. 3. Fill in the break-apart numbers and write the sum.1. 2.9+9= 8+7= 9+6= to make ten the rest to make ten the rest to make ten the rest4. 5. 6.7+6= 8+5= 6+6=to make ten the rest to make ten the rest to make ten the restChapter 1 Lesson 10 OA.2 Adding in Two Steps 21

Color the dots and draw an arrow to make a ten.Fill in the break-apart numbers and write the sum. 1. 2. 3. 9+8= 7+5= 7+7= to make ten the rest to make ten the rest to make ten the rest4. 5. 6. 6+5= 8+8= 7+4= to make ten the rest to make ten the rest to make ten the restFill in the math puzzle and write the number sentence.Use a for the unknown number. Solve.7. Bob has 8 picture books. Whole He also has 8 storybooks. How many book does Bob have in all? Number sentence: _______________ Part Part Bob has ___ books in all.22

Practice: Addition with Teen SumsColor the dots and draw an arrow to make a ten.Fill in the break-apart numbers and write the sum. 1. 2. 3.9+9= 8+7= 9+6=to make ten the rest to make ten the rest to make ten the restAdd.Remember: We can think of the greater number first.4. 7. 10. 6+9= 3+8= 7+9=5. 8. 11. 5+9= 6+8= 8+9=6. 9. 12. 3+9= 7+8= 4+9=13. 16. 19. 5+7= 5+6= 5+8=14. 17. 20. 6+7= 6+6= 4+8=15. 18. 21. 4+7= 4+6= 8+8=Chapter 1 Lesson 11 OA.2 Practice: Addition with Teen Sums 23

Circle each number sentence whose sumis more than ten. Add. 1. 6 2. 6 3. 8 4. 8 5. 9 6. 7 +3 +5 +1 +4 +9 +2 7. 8 8. 6 9 7 10. 4 11. 9 12. 6 +9 +4 +5 +4 +7 +913. 7 14. 9 15. 8 16. 6 17. 4 18. 8 +3 +5 +6 +2 +7 +7 LET’S WRITE! Look at exercise number 18. Explain how you solved 8 + 7.24

8+6= Using the Number Line to Add We make two jumps on the number line: First we jump to the ten. +6 8Complete the number line. Fill in the sum. 1. +7 9+7= 9 +52. 8 8+5= +63. 9+6= 9 +74. 7+7= 7 Using the Number Line to Add 25Chapter 1 Lesson 12 OA.2

Complete the number line. +5Fill in the sum. 1. 6+5= 6 +52. 7+5= 7 +8 3. 8 8+8=ON YOUR OWN! 4. 8+7=Add. 6. 8 7. 6 8. 2 9. 7 10. 4 +5 +6 +9 +7 +8 5. 9 +826

Add. Choosing a Strategy to Add7+6= Which way works best for you? I like to use the I like to use the Dot Card. break-apart number sentence. 7 + 6 = 13 33 to make ten the rest I like to use the number line. +6 +3 13 +3 10 7Circle the way that works best for you. Solve.1. 8 + 6 = 2. 7+5= 8+6= 7+5= to make ten the rest to make ten the rest +6 +58 7Chapter 1 Lesson 13 OA.2 Choosing a Way to Add 27

Add. Choose the way that works best for you. Solve.1. 9 + 7 = 2. 6 + 6 = 9+7= 6+6= to make ten the rest to make ten the rest +7 +6 9 6Add. 4. 4 5. 7 6. 6 7. 7 8. 3 +7 +6 +5 +7 +83. 9 +8Write the number sentence and solve. ¢ 9. Pat had 8¢. Her dad gave her another 5¢. How much money does she have now? Number sentence:28

Adding with Three AddendsThese are Team A’s points. ,¿UVWDGGHGWR Add to find the total. make a ten. 73 4+ 7 + Suzy +I added 10 3 = 14 pointsthe numbers 4 = 14in order. ,¿UVWDGGHG Bella to make a doubles fact.4 + 7 + 3 = 14 points Kelly11 + 3 = 14 4+ 7+ 3 = 14 points + 7 = 14 7We can add in any order and get the same sum.Circle the addends you will add first.Add. Then add the rest.Then solve again, adding in a different order.1. 8 + 7 + 2 = 8+7+2=+= +=2. 7 + 4 + 5 = 7+4+5= += +=3. 1 + 8 + 9 = 1+8+9= += +=Chapter 1 Lesson 14 OA.2 Adding with Three Addends 29

Circle the addends you will add first.Add. Then add the rest.Then solve again, adding in a different order.1. 6 + 5 + 4 = 2. 8 + 6 + 3 = += +=3. 7 + 9 + 2 = 4. 7 + 5 + 1 = += +=5. 8 + 5 + 6 = 6. 3 + 6 + 6 = + = += 8. 7 + 6 + 2 =Add.7. 5 + 3 + 4 =9. 5 + 8 + 5 = 10. 4 + 8 + 5 =11. 8 + 3 + 8 = 12. 9 + 6 + 2 =13. 1 + 7 + 6 = 14. 6 + 4 + 9 =Write the number sentence. Solve.15. Judy has 8 red buttons, 4 green buttons, and 3 purple buttons. How many buttons does Judy have? + += Judy has buttons.30

Subtracting from Teen NumbersSubtract.1. 8 2. 18 3. 6 4. 16 5. 7 6. 17–4 – 4 –5 – 5 –3 – 37. 9 8. 19 9. 4 10. 14 11. 5 12. 15–4 – 4 –3 – 3 –4 – 4Write the number sentence that will help you solve the exercise.Solve.13. 18 – 6 = 14. 17 – 4 = –= –=15. 19 – 5 = 16. 18 – 5 = –= –=17. 19 – 7 = 18. 17 – 6 = –= –=Chapter 1 Lesson 15 OA2 Subtracting from Teen Numbers 31

Subtract. 2. 3. 4. 1. 19 – 6 = 18 – 7 = 17 – 2 =15 – 3 = 5. 6. 7. 8.16 – 5 = 17 – 4 = 19 – 8 = 18 – 6 = 9. 10. 11. 12.15 – 5 = 16 – 4 = 18 – 5 = 19 – 3 =13. 14. 15. 16.14 – 2 = 19 – 4 = 17 – 5 = 16 – 1 =Fill in the math puzzle and write the number sentence. WholeUse a for the unknown number. Solve.17.Boris has 18 yo-yos. 4 yo-yos are glow-in-the-dark. The rest are not glow-in-the-dark. How many yo-yos are not glow-in-the-dark?Number sentence: Part Part yo-yos are not glow-in-the-dark.18. There are 15 children in the yard. Whole 4 are playing with sidewalk chalk. Part Part The rest are playing jump rope. How many children are playing jump rope? Number sentence: children are playing jump rope.32

Subtracting in Two StXepxsx15 – 6 = 9 When we subtract more than the ones51 we have, we subtract in two steps.to get to ten the rest First we subtract all the ones and get to ten. Then we subtract the rest from the ten to find the difference. We break apart the 6. 5 and 1 are the break-apart numbers.Cross off the dots you need to subtract.Fill in the break-apart numbers and write the difference. 1. 2. 3.15 – 7 = 14 – 5 = 11 – 4 = to get to ten the rest to get to ten the rest to get to ten the rest4. 5. 6.12 – 4 = 11 – 5 = 12 – 5 =to get to ten the rest to get to ten the rest to get to ten the restChapter 1 Lesson 16 OA.2 Subtracting in Two Steps 33

Cross off the dots you need to subtract.Fill in the break-apart numbers and write the difference. 1. 2. 3.16 – 7 = 14 – 6 = 13 – 4 = to get to ten the rest to get to ten the rest to get to ten the rest4. 5. 6.13 – 5 = 15 – 6 = 13 – 6 =to get to ten the rest to get to ten the rest to get to ten the restFill in the math puzzle and write the number sentence.Use a for the unknown number. Solve.7. There were 16 apples in a basket. Whole 7 apples were sold. How many apples are in the basket now? Number sentence: Part Part There are ______ apples are in the basket.34

Practice: Subtracting in Two StepsCross off the dots you need to subtract.Fill in the break-apart numbers and write the difference. 1. 2. 3.14 – 6 = 12 – 5 = 13 – 6 = to get to ten the rest to get to ten the rest to get to ten the rest4. 5. 6.13 – 5 = 15 – 6 = 11 – 4 =to get to ten the rest to get to ten the rest to get to ten the restLET’S WRITE!Look at exercise number 1. Explain how you solved 14 – 6.___________________________________________________________________________________________________________________________________________________________________________Chapter 1 Lesson 17 OA.2 Practice: Subtracting in Two Steps 35

Subtract. 3. 1. 12 – 2 = 14 – 4 = 4. 2. 12 – 4 = 14 – 5 = 7. 5. 13 – 3 = 15 – 5 = 8. 6. 13 – 5 = 15 – 6 =Subtract. 10. 11. 12. 13. 14. 9. 17 15 15 13 13 –8 –5 –7 –3 –4 17 –715. 16. 17. 18. 19. 20. 16 16 14 14 12 12 –6 –7 –4 –6 –2 –3Practice. 22. 23. 24. 25. 21. 13 12 12 19 –6 –5 –6 –9 11 –536

Using the Number Line to Subtract We make 2 jumps back. First we jump back to the ten. Then we jump back the rest.15 – 7 = –7 15Cross off the dots you need to subtract.Complete the number line. Write the difference. –51. 12 – 5 = 122. –6 14 – 6 = 14 –73. 16 – 7 = 16 –54.Chapter 1 14 – 5 = 14 Lesson 18 OA.2 Using the Number Line to Subtract 37

Complete the number line. Write the difference. –6 1. 15 15 – 6 = –4 12 2. –6 12 – 4 = 12 3. 12 – 6 =ON YOUR OWN! 4. 13 – 6 = 7. 12 8. 12 9. 11 10. 13 –5 –3 –4 –4Subtract.5. 14 6. 13 –6 –538

Choosing a Way to Subtract Subtract. Which way works best for you?14 – 6 = I like to use I like to break-apart use the numbers. Dot Card. 14 – 6 = 8 42 to get ten the rest I like to use the number line. –6 –2 –4 8 10 14Circle the way that works best for you. Subtract.1. 13 – 5 = 2. 15 – 7 = 13 – 5 = 15 – 7 = to get to ten the rest to get to ten the rest -5 -7 13 15Chapter 1 Lesson 19 OA.2 Choosing a Way to Subtract 39

Circle the way that works best for you. Subtract.1. 13 – 6 = 2. 14 – 7 = 14 – 7 = 13 – 6 = to get ten the rest to get ten the rest –7 –6 14 13Subtract. 4. 5. 6. 7. 3. 11 13 11 14 –4 –4 –6 –5 15 –7Fill in the math puzzle and write the number sentence.Use a for the unknown number. Solve.8. Pat has 15 flowers. 8 flowers are in a vase. Whole The rest are in a basket. Part Part How many flowers are in a basket? Number sentence: ______ flowers are in a basket.40

Subtracting a Lot from a Teen Number When we subtract a lot, we can cross off dots only on the tens side and see how many dots are left on both sides.13 – 8 = 5Cross off the dots you need to subtract. Write the difference. 1. 2. 3. 16 – 9 = 14 – 8 = 18 – 10 =4. 5. 6. 11 – 7 = 13 – 9 = 12 – 7 =7. 8. 9.15 – 9 = 13 – 7 = 16 – 8 =Chapter 1 Lesson 20 OA.2 Subtracting a Lot from a Teen Number 41

Subtract. You can use the Dot Cards to help.1. 3. 5. 14 – 10 = 17 – 10 = 18 – 10 =2. 4. 6. 14 – 9 = 17 – 9 = 18 – 9 =7. 9. 11. 12 – 10 = 13 – 10 = 11 – 10 =8. 10. 12. 12 – 9 = 13 – 8 = 11 – 9 =Practice.13. 14. 15. 16. 17. 18. 16 11 14 11 13 12 –10 – 8 – 8 – 7 – 7 – 8LET’S WRITE!Look at exercise number 18. Explain how you solved 12 – 8._________________________________________________________________________________________________________________42

Mixed Practice: Teen SubtractionWhen we subtract more than the ones there are,we can subtract in two steps. 13 13 –4 –8 95First we subtract all the ones, and then or we can subtractwe subtract the rest from the tens side, only on the tens side.Decide how to subtract. Cross off the dots and write the difference.1. 14 2. 14 3. 14 –5 –9 –84. 12 5. 12 6. 12 –5 –8 –37. 11 8. 11 9. 11 –9 –4 –610. 13 11. 13 12. 13 –5 – 10 –7Chapter 1 Lesson 21 OA.2 Mixed Practice: Teen Subtraction 43

Decide how to subtract. Cross off the dots and write the difference.1. 15 2. 15 3. 15 –6 –8 –94. 12 5. 12 6. 12 – 10 –6 –9Subtract. 8. 16 9. 13 10. 14 11. 13 –7 –4 –5 –6 7. 16 –612. 17 13. 17 14. 12 15. 13 16. 15 – 10 – 9 – 8 – 7 – 9Fill in the math puzzle and write the number sentence.Use a for the unknown number. Solve.17. There were 14 ladybugs on a log. Whole 7 of them crawled away. How many ladybugs are on the log now? Number sentence: Part Part ______ ladybugs are on the log now.44