Order of Operations
Total Page:16
File Type:pdf, Size:1020Kb
Order of Operations ACTIVITY ACTIVITY 2.9 Investigative A Fairly Ordered Operation 2.9 SUGGESTED LEARNING STRATEGIES: Close Reading, Think Order of Operations Aloud, Marking the Text, Summarize/Paraphrase/Retell, Quickwrite My Notes Activity Focus • Order of Operations Ayana and Zachary Wilson are excited about going to the Pace County Fair. General admission to the fair is $8.00 per person. Materials It covers visiting exhibits and some entertainment. Tickets for • No special materials are needed. rides and games must be bought separately. Food and drinks are purchased at the concession stands. A ride ticket costs $3.00. Chunking the Activity 1. Ayana loves to make lists of things to do to prepare for an #1 #8 #12 activity. She made the following list for the morning of the fair. #2–4 #9 #13 #5 #10 #14 To Do Order #6–7 #11 #15 Comb my hair 8 Take a shower 2 Paragraph Close Reading, Brush my teeth 1 Think Aloud, Marking the Text, Eat breakfast 6 Summarize/Paraphrase/Retell Put my clothes on 3 1 Quickwrite After the students 10 Buy my tickets for the fair give the order of the steps it is Put on my shoes 5 very important that they explain Put on my socks 4 why the order of the steps is Ride to the fair 9 important. Get money out of piggy bank 7 a. TEACHER TO YouY could have students Order the steps as you think Ayana will complete them. TEACHER Answers may vary. Sample answer: See table above. writew each step on a stickysticky notenote or an index card so b. Explain why the order of steps is important. they can easily play around with Answers may vary. Sample answer: Some things have to be done before others, such as putting on socks before shoes. the order of the steps before 2. Ayana plans to go on 5 rides. She wrote the numerical entering the order in the student © 2010 College Board. All rights reserved. expression 8 + 5 × 3 to represent the cost of her rides and book. admission to the fair. 2 Close Reading, Guess and a. What is the total cost of Ayana’s admission to the fair and the rides she wishes to go on? Check, Quickwrite The intent of $23 this question (and the next two) is to show a need for an agreement b. Do you think her expression represents this total cost? on the order in which operations Explain. should be performed. After com- Answers may vary. Sample answer: Yes, if you multiply fi rst. pleting this fi rst set of questions, Unit 2 • Operations with Numbers 115 students will learn that multiplica- tion should be performed before 115-122_SB_MS1_2-9_SE.indd 115 12/16/09 5:57:07 PM addition. © 2010 College Board. All rights reserved. © 2010 College Board. Unit 2 • Operations with Numbers 115 1115-122_SB_MS1_2-9_TE.indd15-122_SB_MS1_2-9_TE.indd 111515 22/3/10/3/10 66:32:05:32:05 PPMM ACTIVITY 2.9 Order of Operations ACTIVITY 2.9 Continued continued A Fairly Ordered Operation A Fairly Ordered Operation 3 Close Reading, Guess and SUGGESTED LEARNING STRATEGIES: Close Reading, Guess Check, Quickwrite and Check, Quickwrite, Work Backward My Notes 4 Debrief Students should 3. determine that multiplication Zachary intends on going on 8 rides in the morning and 5 rides in the aft ernoon. He wrote the expression 8 + 5 × 3 should come before addition. to represent the total cost of the rides he wishes to go on. Students should also determine that the way expressions are a. What is the total cost of Zachary’s rides? written is important. $39 b. Do you think his expression represents this total cost? 5 Close Reading, Guess and Explain. Check, Quickwrite Students Answers may vary. Sample answer: Yes, if you add fi rst. should be able to explain that 4. multiplication is performed before Is it a problem that both Ayana and Zachary used the same mathematical expression to represent two diff erent costs? addition. Explain. Answers may vary. Sample answer: Yes, because the 6 Close Reading, Guess and expressions have different values and it is not clear which Check, Quickwrite With this is correct. question, students’ understanding Mathematicians have agreed that when evaluating an expression containing both addition and multiplication the operation of of order of operations for adding multiplication should be performed fi rst. and subtracting continues to be developed. 5. Can Ayana use the expression 8 + 5 × 3 to represent the cost of her admission ticket and rides or can Zachary use it to represent the cost of his rides? Explain. Ayana, because multiplication must be performed before addition. Th e day of the fair both Ayana and Zachary realized that they had not fi gured food into the cost of going to the fair. 6. Ayana has $100 in her piggy bank. She took $60 out to go to the fair. Th en her dad gave her $5 allowance. She does not need this $5 for the fair so she puts it in her piggy bank. Ayana wrote the expression 100 - 60 + 5 to represent the amount of money that © 2010 College Board. All rights reserved. © 2010 College Board All rights reserved is now left in her bank. a. What is the total amount left in Ayana’s piggy bank? $45 b. Do you think her expression represents this total amount? Explain. Answers may vary. Sample answer: Yes, you can add or subtract fi rst and the answer is the same. 116 SpringBoard® Mathematics with Meaning™ Level 1 115-122_SB_MS1_2-9_SE.indd 116 12/16/09 5:57:10 PM115-122_SB_MS1_2-9_SE.indd 117 12/16/09 5:57:12 PM © 2010 College Board. All rights reserved. © 2010 College Board. 116 SpringBoard® Mathematics with Meaning™ Level 1 1115-122_SB_MS1_2-9_TE.indd15-122_SB_MS1_2-9_TE.indd 111616 22/3/10/3/10 66:32:06:32:06 PPMM Order of Operations ACTIVITY 2.9 ACTIVITY 2.9 Continued A Fairly Ordered Operation A Fairly Ordered Operation continued SUGGESTED LEARNING STRATEGIES: Close Reading, 7 Guess and Check, Quick- Guess and Check, Work Backward, Quickwrite, Think write Some students may see Aloud, Marking the Text, Summarize/Paraphrase/Retell My Notes that enclosing 60 + 5 in parenthe- ses and then subtracting from 100 7. Zachary has $100 in his piggy bank. He took $60 out for rides, makes the expression true. food, and admission to the fair, and he took $5 out for a souvenir. Zachary wrote the expression 100 - 60 + 5 to represent the amount of money now left in his bank. TEACHER TO AfterA Question 7 would TEACHER a. What is the total amount left in Zachary’s piggy bank? beb a good time to have $35 studentsstudents connectc mathematical properties and order of operations b. Do you think his expression represents this total amount? to the rules by which they play a Explain. Answers may vary. Sample answer: No, because you should game, such as soccer, chess, or not add when you take something away. volleyball. Th ink about the order in which operations should be performed. When evaluating a numerical expression with addition and Paragraph Close Reading subtraction, the operations of addition and subtraction should be performed in the order in which they appear from left to right. 8 Guess and Check, Quick- 8. Does the expression 100 - 60 + 5 represent the amount left in write Students will use what they Ayana’s bank or the amount left in Zachary’s bank? Explain. just learned about the order in It represents the amount in Ayana’s bank: 100 - 60 + 5 = 45. which to do addition and subtrac- Aft er that Zachary decided to take only $60 to the fair. tion to do this problem. Ayana and Zachary’s mom decided they needed to take some Paragraph Close Reading, snacks to the fair. She took a bag of 6 granola bars and divided . the bars evenly into three sacks. She did the same thing with three Summarize/Paraphrase/Retell more bags of 6 granola bars, sharing them evenly into the same reserved three sacks. She then gave Ayana and Zachary each a sack. 9 This question gives students rights All . practice in deciding the order in 9. When Ayana asked Zachary how many granola bars were in Board each sack, he said the expression 6 ÷ 3 × 4 represented the which to perform multiplication number of granola bars. and division. College 2010 a. © © 2010 College Board. All rights reserved. Ayana evaluated the expression and said the bag contained less than 1 whole granola bar. Explain how she arrived at this answer. Answers may vary. Sample answer: 6 ÷ 3 × 4 = 6 ÷ 12 = .5. b. How many granola bars were actually in each bag? Explain how Zachary derived his expression. Explanations may vary. Sample answer: 8 bars; 6 bars ÷ 3 = 2; 2 × 4 bags of bars = 8. Unit 2 • Operations with Numbers 117 115-122_SB_MS1_2-9_SE.indd 116 12/16/09 5:57:10 PM115-122_SB_MS1_2-9_SE.indd 117 12/16/09 5:57:12 PM © 2010 College Board. All rights reserved. © 2010 College Board. Unit 2 • Operations with Numbers 117 1115-122_SB_MS1_2-9_TE.indd15-122_SB_MS1_2-9_TE.indd 111717 22/3/10/3/10 66:32:07:32:07 PPMM ACTIVITY 2.9 Order of Operations ACTIVITY 2.9 Continued continued A Fairly Ordered Operation A Fairly Ordered Operation Paragraph Close Reading, SUGGESTED LEARNING STRATEGIES: Close Reading, Think Think Aloud, Marking the Text, Aloud, Marking the Text, Summarize/Paraphrase/Retell, Summarize/Paraphrase/Retell My Notes Guess and Check, Create Representations 0 Guess and Check, Create Numerical expressions can contain the operations of addition, ACADEMIC VOCABULARY subtraction, multiplication, and division, so it is important to Representations This is a sum- The order of operations is follow an order of operations to avoid confusion.