Family Letters. Assessment Management. Ongoing Learning & Practice. Playing Equivalent Fractions or Fraction Top-It

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1 Making Change Objective To provide experience making change by counting up and estimating totals by rounding to the nearest 10 cents. epresentations etoolkit Algorithms Practice EM Facts Workshop Game Family Letters Assessment Management Common Core State Standards Curriculum Focal Points Interactive Teacher s Lesson Guide Teaching the Lesson Ongoing Learning & Practice Differentiation Options Key Concepts and Skills Write money amounts in dollars-and-cents notation. [Number and Numeration Goal 2] Count up to make change. [Operations and Computation Goal 2] Estimate and share solution strategies for finding change. [Operations and Computation Goal 3] Key Activities Children estimate and find the exact total cost of several grocery items. They estimate and find the exact change from a $10 bill. Informing Instruction See page 755. Key Vocabulary counting up to make change Materials Math Journal 2, pp. 230, 246, and 247 Home Link 10 5 Math Masters, pp. 310 and 441 (optional) transparency of Math Masters, p. 441 (optional) slate coins and bills calculator Playing Equivalent Fractions or Fraction Top-It Math Journal 2, pp. 198, 199, 203, and 204 per partnership: 32 Fraction Cards (2 sets cut from Math Journal 2, Activity Sheets 5 and 6) Children identify equivalent fractions and compare pairs of fractions. Math Boxes Math Journal 2, p. 245 Children practice and maintain skills through Math Box problems. Recognizing Student Achievement Use Math Boxes, Problem 3. [Measurement and Reference Frames Goal 5] Home Link Math Masters, p. 311 Children practice and maintain skills through Home Link activities. READINESS Finding Distances between Pairs of Numbers on the Number Grid Number-Grid Poster Children explore a counting up strategy for finding the difference between two amounts. ENRICHMENT Exploring Money Amounts Math Masters, p. 312 Math Journal 2, p. 230 calculator Children use the Good Buys Poster to estimate, add, and subtract money amounts. Advance Preparation The Math Message problems also appear on Math Masters, page 310. If you use the Teaching Master, make 1 copy for every 2 children. Change the directions to Take a slip of paper. Complete the problems. With activities involving the Good Buys Poster, you may want to make copies or use an overhead transparency of Math Masters, page 441. For a mathematics and literacy connection, obtain copies of Alexander, Who Used to Be Rich Last Sunday by Judith Viorst (Aladdin, 1980) and Follow the Money by Loreen Leedy (Holiday House, 2002). Teacher s Reference Manual, Grades 1 3 p. 106 Lesson 753

2 Getting Started Mathematical Practices SMP1, SMP3, SMP4, SMP5, SMP6, SMP7 Content Standards 2.OA.1, 2.MD.8 Mental Math and Reflexes Write problems like the following on the board. Children record estimates on their slates. For each problem, have children explain how they arrived at their estimates. Suggestions: $ $0.99 =? $ $ $ $0.39 =? $ $ $ $0.42 =? $ $ $ $0.63 =? $ $ $ $4.59 =? $ $ $ $2.29 =? $ $ Math Message cents cents a dollar forty-seven dollars and 2 cents nine hundred thirty-three dollars and thirty cents three thousand five hundred forty-six dollars and sixteen cents = $ 3, Home Link 10 5 Follow-Up Briefly review estimation strategies and answers. 1 Teaching the Lesson Math Message Follow-Up (Math Masters, p. 310) WHOLE-CLASS DISCUSSION Discuss children s responses and review concepts as needed. Teaching Student Master Page Name Date Name: Math Message cents cents 4. a dollar forty-seven dollars and 2 cents 6. nine hundred thirty-three dollars and thirty cents 7. three thousand five hundred forty-six dollars and sixteen cents , Name: cents cents 4. a dollar forty-seven dollars and 2 cents 6. nine hundred thirty-three dollars and thirty cents three thousand five hundred forty-six dollars and sixteen cents 3, Using Coins and Bills to Make Change from $10.00 WHOLE-CLASS Pose the following problem: I bought soup and a sandwich for $6.32 (including tax). I gave the cashier a $10 bill. Ask children to estimate the amount of change. Record several of their estimates on the board About $3.70; between $3.00 and $4.00; about $4.00. Ask children to find the exact amount of change. $3.68 Have children share their strategies. Use coins and bills to demonstrate the process of counting up to make change: Begin with the amount owed, and count up to the amount given to the cashier. One way to count up from $6.32 to $10.00 would be as follows: $6.33 (1 ), $6.34 (2 ), $6.35 (3 ), $6.45 (13 ), $6.50 (18 ), $6.75 ( = 43 ), $7.00 ( = 68 ), $8.00 ($1.68), $9.00 ($2.68), $10.00 ($3.68). The change is $3.68. Math XXXXXXXXX, Masters, p. p. XXX Unit 10 Decimals and Place Value

3 Date Informing Instruction Watch for children who are having difficulty making an estimate. Ask such questions as the following to help children close in on an estimate. For each question, ask children to explain how they know the answer. Should I get more or less than $10.00 in change? less Should I get more or less than $1.00 in change? more Should I get more or less than $3.00 in change? more Should I get more or less than $4.00 in change? less 10 1 Good Buys Poster Fruit/Vegetables Group Seedless Grapes 99 lb Plums lb Oranges $1.49 lb Watermelons $2.99 ea. Carrots 1-lb bag 3/$1.00 Celery 59 lb Bananas 59 lb Pork & Beans 2/89 Ground Beef $1.99 lb Meat Group Chunk Light Tuna 6.5 oz Milk Group Peanut Butter 18-oz jar $1.29 Lunch Meat 1-lb package $1.39 There are many other ways to count up to make change, for example, by adding dimes ($6.42, $6.52, and so on). Have children use their calculators to check the answer by subtracting the amount owed from $ Demonstrate this routine for one or two other purchases. Then have partners practice this procedure (estimate, count out change, use a calculator to check) with several other amounts. NOTE Although most cash registers display the amount of change, it is useful to learn to make change without the help of a cash register or calculator. It takes time and experience to develop the making-change skill. Saltines 1 lb Grain Group Wheat Bread 99 Hamburger Buns Math Journal 2, p. 230 Gallon Milk $2.39 Mayonnaise 32 oz $1.99 American Cheese 8 oz $1.49 Catsup 32 oz $ pack Yogurt $2.09 Miscellaneous Items Grape Jelly 2-lb jar $1.69 Shopping for Groceries (Math Journal 2, pp. 230, 246, and 247; Math Masters, p. 441) PARTNER PROBLEM SOLVING One partner is the shopper, the other is the clerk. Lead the class through the steps on journal page 246. Partners switch roles and repeat the activity with different purchases. Have the class come together to share estimation strategies and ways of finding change. Date Date Making Change Work with a partner. Use your tool-kit coins and bills. One of you is the shopper. The other is the clerk. The shopper does the following: Chooses one item from each food group on the Good Buys Poster on journal page 230. Lists these items on the Good Buys sales slip in the shopper s journal on page 247. Writes the cost of each item on the sales slip. Estimates the total cost of all the items and writes it on the sales slip. Pays with a $10 bill. Estimates the change and writes it on the sales slip. The clerk does the following: Uses a calculator to find the exact total cost. Writes the exact total cost on the sales slip. Gives the shopper change by counting up. Writes the exact change from $10.00 on the sales slip. Change roles and repeat. Making Change continued The Good Buys Store Sales Slip Item Fruit/vegetables group $. Grain group $. Meat group $. Milk group $. Miscellaneous items $. Estimated total cost $. Estimated change from $10.00 $. Exact total cost $. Exact change from $10.00 $. Answers vary. Cost Math Journal 2, p. 246 Math Journal 2, p. 247 Lesson 755

4 Date Math Boxes 1. What number is shown by the blocks? What is the temperature? 25 F Is it warm or cold outside? cold F 5. Write the names of 3 objects that are shaped like cylinders. 229_262_EMCS_S_SMJ_G2_U10_57640X.indd 245 soup cans, jars, Joe has $1.00 and spends 65. How much change will he get? 4. You buy some stickers for $1.89. Show 2 ways to pay. Use Î, Â, Í,, and Á. 6. How many in all? Fill in the multiplication diagram. rows 35 Á ÍÎ ÎÎÎ or Á ÍÍÍÂ ÎÎÎÎ 15 per row in all mugs, pencils Math Journal 2, p /3/11 7:37 AM 2 Ongoing Learning & Practice Playing Equivalent Fractions or Fraction Top-It (Math Journal 2, pp. 198, 199, 203, and 204) PARTNER Children practice identifying equivalent fractions in Equivalent Fractions. Children practice comparing fractions in Fraction Top-It. For detailed instructions, see Lessons 8-5 and 8-6. Another version of each game is provided. Math Boxes (Math Journal 2, p. 245) Mixed Practice Math Boxes in this lesson are linked with Math Boxes in Lessons 10-8 and The skill in Problem 6 previews Unit 11 content. Writing/Reasoning Have children draw, write, or verbalize their answers to the following: In Problem 3, what temperature would it be if it were 20 F warmer? Show your work and explain what you did. Sample answer: 45 F. 10 warmer is 35, and another 10 is 45. Home Link Master Name Date Recognizing Student Achievement Math Boxes Problem 3 Use Math Boxes, Problem 3 to assess children s ability to read the temperature. Children are making adequate progress if they correctly complete the box. Some children may be able to identify the equivalent Celsius temperature on a classroom thermometer. [Measurement and Reference Frames Goal 5] HOME LINK Making Change Family Note In today s lesson, your child made change by counting up. When counting out change, encourage your child to begin with the cost of the item and count up to the amount of money that the customer has given to the clerk. For the example listed in the table below, your child could do the following: 1. Say 89 cents the price of the item. 2. Put a penny on the table and say 90 cents. 3. Put a dime on the table and say $ Count the coins on the table = 11. The change is 11. Please return this Home Link to school tomorrow. Materials coins and bills (You can make bills out of paper.) items with prices marked Practice making change with someone at home. Pretend you are the clerk at a store and the other person is a customer. The customer buys one of the items and pays with a bill. You count out the change. Record some purchases here. Item Price Amount Used Change to Pay Home Link (Math Masters, p. 311) Home Connection Children pretend that they are clerks in a store and ask someone at home to be the customer. The customer pretends to buy several items (groceries or other things). Children practice counting out the change for each item. If possible, they go to a store, buy something, and get change. can of $0.89 $1.00 $0.11 black beans Answers vary. If possible, go to the store with someone. Buy something and get change. Count the change. Is it correct? Math Masters, p _EMCS_B_MM_G2_U10_ indd 311 3/1/11 4:29 PM 756 Unit 10 Decimals and Place Value

5 3 Differentiation Options READINESS Finding Differences between Pairs of Numbers on the Number Grid SMALL-GROUP 5 15 Min To explore a counting up strategy for finding the difference between two amounts, have children find the distance between pairs of numbers on the number grid. Pose such problems as the following: Start at 30. How many spaces on the number grid is it to 57? I put my finger on 30. I moved one row down, to 40. That s 10 spaces. Then I moved down one more row to 50. That s 10 more, so I ve moved 20 spaces. Then I moved to the right one space at a time and counted, until I got to 57 that s 21, 22, 23, 24, 25, 26, 27. So it is 27 spaces from 30 to 57. Have children describe how they navigate on the grid and count up to arrive at their answers. Class Number Grid Count: 10, 20, 21, 22, 23, 24, 25, 26, 27 ENRICHMENT Exploring Money Amounts (Math Masters, p. 312; Math Journal 2, p. 230) Min To apply children s knowledge of adding and subtracting money amounts, use the Good Buys Poster and pose 1- and 2-step number stories. Suggestions: Mallory went to the store to buy 1 pound of seedless grapes. The clerk gave her $9.01 change. How much did Mallory give the clerk? $10.00 and Kevin went to the store with some money. He bought bananas and peanut butter. He left the store with $3.12. How much did Kevin bring to the store? $5.00 When children feel comfortable solving these problems, have them complete Math Masters, page 312. Children use the Good Buys Poster and find objects that total a given amount. Name Date Teaching Master What Did They Buy? Using the Good Buys Poster, find the items each child could have bought with the total they spent. 1. Peter went shopping for his mom. He bought ground beef, tuna, mayonnaise, hamburger buns, and wheat bread. If he spent a total of $9.73, what are two other items that he could have bought? Show your work. Sample answer: 1 pound of grapes and 1 gallon of milk $ $ $ $ $ $ $ $ $ Sarah had $ She spent $9.45 at the market. What could Sarah have bought? Show your work. Sample answer: watermelon, peanut butter, lunch meat, yogurt, and grape jelly $ $ $ $ $ Kevin had $12.00 when he went to the market. He left the store with $2.37 in change. What might he have bought? Show your work. Sample answer: mayonnaise, lunch meat, wheat bread, American cheese, gallon of milk, 2 pounds of plums $ $ $ $ $ $ Math Masters, p. 312 Lesson 757