U.S. Traditional Long Division, Part 1 Algorithm Objective To introduce U.S. traditional long division. Project Projject www.everydaymathonline.com eToolkit Algorithms Practice EM Facts Workshop Game™ Family Letters Assessment Management Common Core State Standards Curriculum Focal Points Interactive Teacher’s Lesson Guide Doing the Project Recommended Use After Lesson 610 Key Concepts and Skills • Subtract multidigit numbers. [Operations and Computation Goal 2] • Apply multiplication facts to long-division situations. [Operations and Computation Goal 3] • Solve equal-sharing division problems and number stories. [Operations and Computation Goal 4] Key Activities Materials Math Journal 1 or 2, pp. 25P–27P Student Reference Book, pp. 24E–24H $1 and $10 bills (Math Masters, p. 428; optional) $100 bills (optional) coins (optional) base-10 blocks (optional) index cards (optional) Students explore and practice U.S. traditional long division with two- and three-digit whole numbers divided by single-digit whole numbers. Key Vocabulary U.S. traditional long division dividend divisor quotient remainder Extending the Project Ex Students write and solve division number stories using U.S. traditional long division. Materials For additional practice, students solve division problems, first using the focus algorithm (partial-quotients division) and then using any algorithm they choose. Student Reference Book, pp. 22– 24 and 24E–24H Online Additional Practice, pp. 27A–27C Advance Preparation If you intend to have students use coins and bills to model the division problems, you will need $100 bills. Make several copies of Grade 3 Math Masters, page 401. Alternatively, use index cards to create $100 bills. Algorithm Project 7 A31_EMCS_T_TLG2_G4_P07_576906.indd A31 A31 4/4/11 9:23 AM Student Page Date Time PROJECT 1 Doing the Project Long Division with One-Digit Divisors 7 Algorithm Project 7 Use any strategy to solve the problem. 1. $ WHOLE-CLASS DISCUSSION ► Solving a Division Problem The fourth-grade classes at Glendale School put on puppet shows for their families and friends. Ticket sales totaled $532, which the four classes are to share equally. How much should each class get? (Math Journal 1 or 2, p. 25P) 133 Be ready to explain how you found your answer. Ask students to solve Problem 1 on journal page 25P. Tell them they may use play money, paper and pencil, or any other tools they wish except calculators. Use U.S. traditional long division to solve each problem. 2. 13 78 / 6 = 188 4. = 564 / 3 3. 5. 288 / 8 = 109 36 Discuss students’ solutions. $532 / 4 = $133 Expect that students will use several different methods, including sharing or other actions with play money or other manipulatives, various informal paper-and-pencil methods, and partial-quotients division. Some students may also use U.S. traditional long division. For example: = 763 / 7 Sharing play money Math Journal, p. 25P 25P-27P_EMCS_S_MJ1_G4_P07_576361.indd 25 3/4/11 11:57 AM &%% &% & & & & & &%% &% & & & & & &%% &% & & &%% &% &% &% &%% &% &% &% &% &% &% &%% &% &%% &%% &%% &% &% &% &% &% &% &% &% &% &% &% &% & & & & & & & & & & & & $532 / 4 = $133 Sharing base-10 blocks $532 / 4 = $133 A32 Algorithm Project 7 U.S. Traditional Long Division, Part 1 A32-A36_EMCS_T_TLG2_G4_P07_576906.indd A32 4/4/11 9:23 AM Using an informal paper-and-pencil method (See margin.) 532 - 100 Using partial-quotients division 4 532 - 400 100 432 - 100 332 - 100 20 232 - 100 132 - 80 52 - 40 10 12 - 12 3 0 133 132 - 100 32 - 32 0 $25 for each class $25 for each class $25 for each class $25 for each class $8 for each class $25 + $25 + $25 + $25 + $25 + $8 = $133 Using U.S. traditional long division 133 4 532 -4 NOTE Long division is very demanding. Encourage students who may be overwhelmed to make a table of easy multiples of the divisor. For example: 13 - 12 12 - 12 1∗4 2∗4 3∗4 4∗4 5∗4 6∗4 7∗4 8∗4 9∗4 0 ► Introducing Long Division $25 for each class WHOLE-CLASS ACTIVITY After discussing students’ solutions, regardless of whether one or more students used U.S. traditional long division, demonstrate it again as described below. Illustrate each step with pictures and, if possible, act out the problem using play money. Help students make connections between the steps in the algorithm and the actions of sharing the money. 4 8 12 16 20 24 28 32 36 Step 1 Step 1: Set up the problem. Think about sharing actual bills: 5 [$100]s, 3 [$10]s, and 2 [$1]s. BdcZnid WZH]VgZY Bh#6Éh 8aVhh Bh#7Éh 8aVhh Bh#8Éh 8aVhh Bg#9Éh 8aVhh Bh#6Éh 8aVhh Bh#7Éh 8aVhh Bh#8Éh 8aVhh Bg#9Éh 8aVhh &%% &%% &%% &%% &%% &%% &%% &%% &%% 4 532 $532 is to be shared. We say $532 is the dividend. Think of $532 as 5 [$100]s, 3 [$10]s, and 2 [$1]s. &% &% & & &% The money is to be shared by four classes. We say 4 is the divisor. Step 2: Step 2 Share the [$100]s. There are 5 [$100]s, so each class gets 1 [$100]. That uses up 4 [$100]s and leaves 1 [$100]. BdcZnid WZH]VgZY &%% 1 4 532 Each class gets 1 [$100]. -4 −−− 1 [$100] each for 4 classes = 4 [$100]s 1 [$100] is left. 1 &% &% & & &% Algorithm Project 7 A32-A36_EMCS_T_TLG2_G4_P07_576906.indd A33 A33 4/4/11 9:23 AM Step 3: Step 3 BdcZnid WZH]VgZY &% &% &% &% &% &% &% &% &% &% &% &% Bh#6Éh 8aVhh Bh#7Éh 8aVhh Bh#8Éh 8aVhh Bg#9Éh 8aVhh &%% &%% &%% &%% 1 4 532 4 −−− &% & & 13 After trading the [$100] for 10 [$10]s, there are 13 [$10]s in all. Step 4: Step 4 BdcZnid WZH]VgZY &% & Trade the remaining [$100] for 10 [$10]s. That makes 13 [$10]s in all. & Bh#6Éh 8aVhh Bh#7Éh 8aVhh Bh#8Éh 8aVhh Bg#9Éh 8aVhh &%% &%% &%% &%% &% &% &% &% &% &% &% &% &% &% &% &% Share the 13 [$10]s. Each class gets 3 [$10]s. That leaves 1 [$10] still to be shared. 13 4 532 Each class gets 3 [$10]s. 4 −−− 13 12 −−−− 1 Step 5: Step 5 BdcZnid WZH]VgZY & & & & & & & & & & 3 [$10]s each for 4 classes = 12 [$10]s 1 [$10] is left. & & Bh#6Éh 8aVhh Bh#7Éh 8aVhh Bh#8Éh 8aVhh Bg#9Éh 8aVhh &%% &%% &%% &%% &% &% &% &% &% &% &% &% &% &% &% &% Trade the last [$10] to be shared for 10 [$1]s. That makes 12 [$1]s in all. 13 4 532 4 −−− 13 12 −−−− 12 Step 6: Step 6 BdcZnid WZH]VgZY A34 After trading the [$10] for 10 [$1]s, there are 12 [$1]s in all. Bh#6Éh 8aVhh Bh#7Éh 8aVhh Bh#8Éh 8aVhh Bg#9Éh 8aVhh &%% &%% &%% &%% &% &% &% &% &% &% &% &% &% &% &% &% & & & & & & & & & & & & Algorithm Project 7 Share the 12 [$1]s. Each class gets 3 [$1]s. 133 4 532 Each class gets 3 [$1]s. 4 −−− 13 12 −−−− 12 12 −−−− 0 3 [$1]s each for 4 classes = 12 [$1]s 0 [$1]s are left. U.S. Traditional Long Division, Part 1 A32-A36_EMCS_T_TLG2_G4_P07_576906.indd A34 4/4/11 9:23 AM Student Page Step 7: Date PROJECT Each class gets $133. We say $133 is the quotient. A number model is a good way to show the answer. Since there is no remainder, either 7 Time Long Division with One-Digit Divisors cont. Algorithm Project 7 6. 350 / 4 → 87 R2 7. 802 / 9 → 89 R1 $532 / 4 → $133 or $532 / 4 = $133 would be an acceptable number model for this problem. U.S. traditional long division is complicated, so you may want to work more examples with the whole class. For now, continue to use sharing money as a context and continue drawing pictures and, if possible, acting out the problems with play money. Later, the algorithm can be generalized to non-money contexts. 124 R1 8. ← 869 / 7 9. 174 R4 ← 874 / 5 Suggestions: $84 / 7 $12 $807 / 4 $201 R$3 $785 / 5 $157 86 / 7 12 R2 $122 / 8 $15 R$2 468 / 5 93 R3 ► Solving Long Division Problems Math Journal, p. 26P 25P-27P_EMCS_S_MJ1_G4_P07_576361.indd 26 3/4/11 11:57 AM PARTNER ACTIVITY with One-Digit Divisors (Math Journal 1 or 2, pp. 25P–27P; Student Reference Book, pp. 24E–24H) When students are ready, have them use U.S. traditional long division to solve Problems 2–13 on journal pages 25P– 27P. They may find the examples on Student Reference Book, pages 24E–24H helpful. Students should note that Problems 6–9 involve remainders. Student Page Date PROJECT 7 Long Division with One-Digit Divisors cont. Algorithm Project 7 2 Extending the Project ► Writing and Solving Division Time 10. 11. Eight people visited a marine theme park. The total cost of the single-day admission tickets was $424. What was the cost per ticket? $ A national park charges an entrance fee of $3 per person. A school group visited the site. The cost was $288. How many people were in the school group? 53 96 people PARTNER ACTIVITY Number Stories (Student Reference Book, pp. 24E–24H) Have students write division number stories for a partner to solve using U.S. traditional long division. Again, students may find the examples on Student Reference Book, pages 24E–24H helpful. 12. 13. A family went on a six-day boat cruise. They sailed a total of 432 miles. They sailed the same distance each day. How far did they travel each day? 72 Four friends have birthdays in the same month. They decide to rent a hall to have a birthday party and split the cost evenly. The cost of renting the hall for one day is $172. How much did each friend pay? miles $ 43 Math Journal, p. 27P 25P-27P_EMCS_S_MJ1_G4_P07_576361.indd 27 3/4/11 11:57 AM Algorithm Project 7 A32-A36_EMCS_T_TLG2_G4_P07_576906.indd A35 A35 4/4/11 9:23 AM Student Page ► Solving Division Problems Whole Numbers U.S. Traditional Long Division INDEPENDENT ACTIVITY (Online Additional Practice, pp. 27A–27C; Student Reference Book, pp. 22–24 and 24E–24H) You can use U.S. traditional long division to divide. $935 4 To begin, think about sharing $935 among 4 people: Aimee, Brad, Carla, and Duane. Money to be Shared Aimee Brad Carla Duane Aimee Brad Carla Duane $100 $100 $100 $100 $100 $100 $100 $100 Online practice pages 27A–27C provide students with additional practice solving division problems. Use these pages as necessary. $100 $100 $100 $100 $100 $100 $100 $100 $100 $10 $10 $10 $1 $1 $1 $1 $1 Encourage students to use the focus algorithm (partial-quotients division) to solve the problems on practice page 27A. Invite them to use any algorithm they wish to solve the problems on the remaining pages. Students may find the examples on Student Reference Book, pages 22–24 and 24E–24H helpful. Step 1: Share the [$100]s. Money to be Shared $100 $10 $10 $10 $1 $1 $1 $1 $1 2 ← Each person gets 2 [$100]s. 4 935 -8 ← 2 [$100]s each for 4 people 1 ← 1 [$100] is left. Step 2: Trade the last [$100] for 10 [$10]s. That makes 13 [$10]s in all. Aimee Brad Carla Duane $10 $10 $10 $10 $10 $100 $100 $100 $100 $10 $10 $10 $10 $10 $100 $100 $100 $100 $10 $10 $10 $1 $1 $1 $1 $1 Money to be Shared 2 4 935 -8 13 ← 13 [$10]s are to be shared. Student Reference Book, p. 24E 024A-024J_EMCS_S_G4_SRB_576507.indd 24E 3/1/11 8:46 AM Go to www.everydaymathonline.com to access the additional practice pages. Student Page Online Master Name Whole Numbers Date PROJECT Online Additional Practice Partial-Quotients Division 7 continued Time Algorithm Project 7 Step 3: Share the [$10]s. Money to be Shared $10 $1 $1 $1 $1 $1 Aimee Brad Carla Duane $100 $100 $100 $100 $100 $100 $100 $100 $10 $10 $10 $10 $10 $10 $10 $10 $10 $10 $10 $10 Use partial-quotients division to solve each problem. 1. Mrs. Johnson has a total of $872 that she wants to divide equally among her 8 grandchildren. How much should each grandchild get? $ 109 ← Each person gets 3 [$10]s. 23 4 935 -8 13 -12 1 2. 78 / 6 = 13 3. 324 / 9 = 36 ← 3 [$10]s each for 4 people ← 1 [$10] is left. Step 4: Trade the last [$10] for 10 [$1]s. That makes 15 [$1]s in all. Brad Carla Duane $1 $1 $1 $1 $100 $100 $100 $100 $1 $1 $1 $1 $1 $100 $100 $100 $100 $1 $1 $1 $1 $1 $10 $10 $10 $10 $10 $10 $10 $10 $10 $10 $10 $10 23 935 4 -8 13 -12 15 Copyright © Wright Group/McGraw-Hill Aimee $1 Money to be Shared ← 15 [$1]s are to be shared. Student Reference Book, p. 24F 4. 146 A36 Algorithm Project 7 5. 126 = 882 / 7 Online Additional Practice, p. 27A EM3cuG4OP_27A-27C_P07.indd 27A 024A-024J_EMCS_S_G4_SRB_576507.indd 24F = 438 / 3 3/31/10 5:34 PM 3/1/11 8:46 AM U.S. Traditional Long Division, Part 1 A32-A36_EMCS_T_TLG2_G4_P07_576906.indd A36 4/4/11 9:23 AM
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