Fractions and Decimals: Part 2 Objective To provide experience with several graphic models ffor renaming fractions as decimals. www.everydaymathonline.com ePresentations eToolkit Algorithms Practice EM Facts Workshop Game™ Teaching the Lesson Key Concepts and Skills • Convert between fractions, mixed numbers, and decimals. [Number and Numeration Goal 5] • Order rational numbers. [Number and Numeration Goal 6] • Order fractions and decimals on a number line. [Number and Numeration Goal 6] Key Activities Students use the Probability Meter and Fraction-Stick Chart to approximate decimal equivalents for fractions. They begin filling in a table of decimal equivalents. Materials Math Journal 1, pp. 142, 205, and the inside back cover Study Link 55 transparencies of Math Masters, pp. 137 and 138 slate straightedge Family Letters Assessment Management Common Core State Standards Ongoing Learning & Practice Converting Improper Fractions with Division Math Journal 1, p. 143 Students review and practice converting improper fractions to mixed numbers using division. Math Boxes 5 6 Math Journal 1, p. 144 Students practice and maintain skills through Math Box problems. Curriculum Focal Points Interactive Teacher’s Lesson Guide Differentiation Options READINESS Playing Number Top-It (3-Place Decimals) Student Reference Book, p. 327 Math Masters, p. 493 per partnership: 4 each of number cards 0–9 (from the Everything Math Deck, if available) Students practice forming and comparing decimals. ENRICHMENT Ongoing Assessment: Recognizing Student Achievement Writing Fraction and Decimal Equivalents for a Shaded 100-Grid Use Math Boxes, Problem 5. Math Masters, pp. 140 and 141 transparency of Math Masters, p. 141 Students write equivalent fractions and decimals for the shaded portion of a 100-grid. [Number and Numeration Goal 6] Study Link 5 6 Math Masters, p. 139 Students practice and maintain skills through Study Link activities. EXTRA PRACTICE 5-Minute Math 5-Minute Math™, p. 93 Students compare fractions, decimals, and percentages. Advance Preparation For Part 1, make transparencies of Math Masters, pages 137 and 138. For the optional Enrichment activity in Part 3, make one transparency of Math Masters, page 141 for each group of six students. Cut apart the transparency grids so that there is one per student. Teacher’s Reference Manual, Grades 4–6 pp. 88, 89, 172 Lesson 5 6 319 Mathematical Practices SMP1, SMP2, SMP3, SMP5, SMP6, SMP7 Content Standards Getting Started 5.NBT.3a, 5.NBT.4, 5.NF.3 Mental Math and Reflexes Math Message Ask questions like the following. Students refer to the Probability Meter on Math Journal 1, page 205 and respond by writing number sentences. How would you use the Probability Meter on journal page 205 to show someone 1 what _ 8 dollar is worth? or _ ?_>_ Which is greater, _ 10 8 8 10 6 5 5 6 Study Link 5 5 Follow-Up or _ ?_>_ Which is greater, _ 8 3 8 3 3 1 3 or _ ?_>_ Which is greater, _ 5 3 5 3 2 2 2 1 2 = 0.875 What fraction is equal to 0.875? _ 8 7 Allow partners five minutes to compare their answers and correct any errors. = 0.625 What fraction is equal to 0.625? _ 8 5 Ask volunteers to share their strategies for rounding the area of Malta to the nearest tenth km2. Highlight that rounding to the nearest tenth rounds 315.98 km2 to the nearest whole number—316.0 km2. ⎯? _ ⎯ = 0.3 What fraction is equal to 0.3 3 1 = 0.05 What fraction is equal to 0.05? _ 20 1 ⎯? _ ⎯ = 0.16 What fraction is equal to 0.16 6 1 ⎯ = 0.83 What fraction is equal to 0.83? _ 6 5 1 Teaching the Lesson 100% 1 .00 0.99 9 5% 0.95 9 0% 0.90 0.875 8 5% 0.85 0.83 8 0% 0.80 75% 0.75 C E R TA I N E L X I T K R E E L M Y E L Y V E R Y L I K E L Y 9— 9 — 100 1 19 — 20 5 — 6 4, — 8 — 5 10 I 7 0% K 0.70 6 5% 7 — 10 E 0.66 2 — 3 L Y 0.65 5 — 8 3, — 6 — 5 10 0.625 6 0% 0.60 5 5% 0.55 50% 0.50 4 5% 0.45 40% 0.40 Ask volunteers to show how they used the Probability Meter to 1 dollar. Use their explanations to discuss the find the value of _ 8 meter’s decimal labels as dollar notation. In dollar notation, hundredths are equivalent to pennies or cents: 1 is 0.25, or 25 cents. The fraction _ 1 is directly opposite the _ 4 8 1 decimal 0.125. Point out that 0.12 is 12 cents and 0.005 is _ 2 1 1 1 1 _ _ _ _ of 100 , or 2 of 1 cent, so 8 dollar is worth $0.125, or 12 2 cents. 3 dollar worth? $0.375, or 37_ 1 cents ● What is _ 8 50–50 CHANCE 0.35 0.33 30% 0.30 25% 0.25 2 0% 0.20 0.16 1 5% 0.15 U N L I K E L Y V E R Y 0.125 1 0% 0.10 5% 0.05 0% 0.01 0. 0 0 1 2 , 3 , 4 , 5 , 10 50 — —, — — — — —, — 2 4 6 8 10 20 100 2, — 4 — 5 10 3 — 8 0.375 3 5% E X T R E M E L Y 1 — 3 3 — 10 2 1, — — 4 8 U N L I K E L Y U N L I K E L Y 1 — 6 1 — 8 1 — 10 1 — 20 —1— 100 0 Probability Meter 320 Unit 5 2 ● 5 dollar worth? $0.625, or 62_ 1 cents What is _ ● 7 dollar worth? $0.875, or 87_ 1 cents What is _ 8 8 2 2 Writing Fractions as Decimals WHOLE-CLASS ACTIVITY (Math Journal 1, p. 142; Math Masters, p. 137) Use a transparency of Math Masters, page 137 to demonstrate how the Fraction-Stick Chart can be used to approximate the decimal names for fractions. 1 — 5 IMPOSSIBLE WHOLE-CLASS DISCUSSION (Math Journal 1, p. 205) 9 — 10 7 — 8 6 3, — — 4 8 L Math Message Follow-Up Fractions, Decimals, and Percents Student Page 2? Example: What decimal is about equal to _ 3 Date Time LESSON 2 . Count the Step 1: Use the thirds row, and locate the fraction _ 3 1 bars from left to right: _ 2 is the right edge of the second bar. _ 3 3 2 ; that is, Step 2: Place one edge of a ruler or straightedge at _ 3 1 piece and perpendicular to the along the right edge of the second _ Writing Fractions as Decimals 5 6 䉬 1 4 0 1 2 1 4 1 6 6 1 1 1 3 1 4 0.2 0.3 1 9 1 12 1 16 0.4 1 10 1 12 1 16 1 10 1 12 1 16 0.5 3 1 8 1 9 1 9 1 16 0.6 1 16 1 9 1 10 1 10 1 12 1 12 1 16 0.7 1 7 1 6 1 7 1 7 1 8 1 12 1 16 1 16 0.3 1 8 1 9 1 10 1 12 1 16 0.4 1 9 1 10 1 12 1 16 1 12 1 16 1 16 0.6 1 8 1 9 1 10 1 12 1 16 1 9 1 10 0.5 1 7 1 8 1 9 1 10 1 12 1 16 1 6 1 7 1 8 1 9 1 10 1 5 1 6 1 10 1 12 1 16 0.7 1 12 1 16 0.8 1 16 0.9 1.0 5. 0.125 1 ᎏᎏ 3 –– 9. 0.75 –– 1.3 11. 3.875 ⫽ 0. 1 ᎏᎏ 8 ⫽ 0. 1 3 9 ᎏᎏ 12 ⫽ 0. 7 5 1 1ᎏ3ᎏ 7 3 ᎏ8ᎏ 4. 0.6 0.8 6. 0.625 2. 0.916 苶 1.375 10. 8. ⫽ 1. 3 3 ⫽ 3. 8 8 4 ᎏᎏ 5 6 7 ⫽ 0. 8 0 5 ᎏᎏ 8 ⫽ 0. 11 ᎏᎏ 12 ⫽ 0. 2 ᎏᎏ 3 ⫽ 0. 3 1 ᎏ8ᎏ 9 2 ⫽ 1. 3 8 –– 12. 9.83 6 3 9.8 3 5 9 ᎏ6ᎏ ⫽ 1 7 1 7 1 8 1 9 1 10 1 16 1 7 1 8 1 6 1 6 1 6 1 7 1 8 1 5 1 10 1 12 1 16 0.8 1 12 1 16 1 16 0.9 1 8 1 9 1 10 1 12 1 16 Math Journal 1, p. 142 1.0 0 inches 0.1 1 6 1 7 1 5 1 5 1 6 1 6 1 1 7 7 1 1 1 8 8 8 1 1 1 9 9 9 1 1 1 10 10 10 1 1 1 1 12 12 12 12 1 1 1 1 1 16 16 16 16 16 1 4 1 5 2 1 6 0.0 1 4 1 5 1 6 0.2 1 4 1 5 3 3 4 0 ᎏᎏ ⫽ 0. 4 10 3. 7. 1 3 1 1 4 1 5 –– 0.3 0.4 1. 4 1 2 1 3 1 4 1 5 0.1 1 3 1 4 1 5 Use a straightedge and the above chart to fill in the blanks to the right of each fraction below. Write a decimal that is equal to, or about equal to, the given fraction. Directions for filling in the blank to the left of each fraction will be given in the next lesson. Sample answers: 2 4 1 2 1 3 1 1 7 7 1 1 1 8 8 8 1 1 1 9 9 9 1 1 1 10 10 10 1 1 1 1 12 12 12 12 1 1 1 1 1 16 16 16 16 16 5 1 4 1 1 2 1 3 0.0 0 3 4 1 3 Decimal Number Line. 2 4 Step 3: Find where the straightedge crosses the number line. It 2 is about 0.67. crosses at about 0.67, so _ 3 Refer students to journal page 142. Ask them to use the chart and number line on the page to mirror the steps as you demonstrate 5. finding the decimal name for _ 8 Ask students how they would use the chart to find the decimal 2 . Use their responses to emphasize that with mixed name for 6_ 3 numbers it is necessary to approximate only the fraction part. The whole number part is unchanged when they write the decimal 2 is about 6.67. name, so 6_ 3 Teaching Master Name Date LESSON Time Fraction-Stick Chart and Decimal Number Line 56 䉬 1 4 0 2 4 3 4 1 1 1 2 1 2 1 3 1 3 1 4 0.1 0.2 1 5 1 6 0.3 1 4 1 5 1 6 1 1 7 7 1 1 1 8 8 8 1 1 1 9 9 9 1 1 1 10 10 10 1 1 1 1 12 12 12 12 1 1 1 1 1 16 16 16 16 16 0.0 1 4 1 5 1 6 Assign students to complete the estimates for each problem on the journal page. Circulate and assist. When most students have finished, review the answers and strategies, and discuss any problems that students found particularly difficult or interesting. 1 3 1 4 1 5 1 7 1 8 1 9 1 7 1 8 1 16 0.4 1 10 1 12 1 16 0.5 1 7 1 8 1 9 1 10 1 12 1 16 1 6 1 7 1 8 1 9 1 12 1 16 1 6 1 7 1 10 1 5 1 6 1 9 1 10 1 12 1 16 0.6 1 16 1 9 1 10 1 12 1 16 0.7 1 10 1 12 1 16 0.8 1 12 1 16 1 16 0.9 1 8 1 9 1 10 1 12 1 16 1.0 NOTE The Fraction-Stick Chart is a useful visual device but is not intended to provide precise equivalencies between all fractions and decimals. In Lesson 5-7, students will use their calculators to find decimal equivalents for fractions. Math Masters, p. 137 Lesson 5 6 321 Teaching Master Name LESSON 56 䉬 Date Filling In a Table of Decimal Time Table of Decimal Equivalents for Fractions Equivalents for Fractions Example: To find the decimal equivalent for ᎏ14ᎏ, use the row for the denominator 4. Go to the column for the numerator 1. The box where the row and the column meet shows the decimal 0.25. (Math Journal 1, inside back cover; Math Masters, p. 138) Numerator 1 2 3 4 1 1.0 2.0 3.0 2 0.5 1.0 1.5 5 6 7 Denominator 3 8 9 10 A partially completed table of decimal equivalents for fractions appears on the inside back cover of the journal and on Math Masters, page 138. 2.3 4 0.25 1.25 5 0.2 1.0 6 Use a transparency of Math Masters, page 138 to show students how the table works. Each number across the top of the table identifies the numerator of a fraction. Each number down the left side of the table identifies the denominator of a fraction. The box where a row and column meet is used to show the decimal equivalent for that fraction. 1.6 7 0.142857 8 0.625 9 10 PARTNER ACTIVITY 0.8 0.1 Have students complete rows 1, 2, 4, 5, and 10. The fractions for the assigned rows are easy fractions. Most students will know their decimal names or will be able to calculate them mentally. Students will complete the rest of the rows in succeeding lessons. Math Masters, p. 138 Numerator 2 3 4 5 6 7 8 9 10 1 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 2 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 4 0.25 0.5 0.75 1.0 1.25 1.5 1.75 2.0 2.25 2.5 5 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 10 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Denominator 1 Inside back cover of Math Journal 1. Completed rows 1, 2, 4, 5, and 10. Student Page Date LESSON 56 Time Converting Improper Fractions to Mixed Numbers In the problems below, the hexagon shape has a value of 1. Whole Write the improper fraction name for each diagram. Use division to find the mixed number. Show your work. hexagon Improper Fraction Mixed Number 9 _ 2 1 4_ 2 14 _ 2 4_ 3 4 R2 ____ 3 14 23 _ 5 3_ 6 ___3 R5 6 23 Example: Show your work. 4 R1 2 9 1. 3 2. 6 1 5_ 3 3 Use division to convert the following improper fractions to mixed numbers or whole numbers. 4. 30 _ 5 = 6 5. 29 _ 4 = _1 74 6. 17 _ 7 = 2 Ongoing Learning & Practice 5 R1 ___ 3. 16 _ Converting Improper Fractions 3 16 _3 3 14 _ Jenny said that she could convert _ 3 to a mixed number by repeatedly subtracting 3 and seeing what was left over. Tell whether you agree or disagree with this method, and explain why. 3 _ Sample answer: I agree. Each time Jenny subtracts 3 , she is taking away a whole. If she writes the number of wholes she subtracts and then writes the remainder as a fraction, she will 2 have the correct mixed number, 4 _ 3. 322 Unit 5 (Math Journal 1, p. 143) Students review and practice converting improper fractions to mixed numbers using division. Math Journal 1, p. 143 121-163_EMCS_G5_S_G5_SMJ_U05_57637X.indd 143 INDEPENDENT ACTIVITY with Division 27 Try This 7. When students have written the decimal names, ask volunteers to describe any patterns that they notice in the table. Sample answers: The rows represent whole numbers, halves, thirds, fourths, etc. The first column represents unit fractions. All boxes on the diagonal from the upper left to the lower right have a value of 1, with decimals greater than 1 in the boxes to the right of this diagonal and less than 1 in the boxes to the left. Decimals become larger as you move across rows and become smaller as you move down columns. 8/29/11 10:19 AM Fractions, Decimals, and Percents Student Page Math Boxes 5 6 Date INDEPENDENT ACTIVITY (Math Journal 1, p. 144) Time LESSON Math Boxes 5 6 䉬 1. Complete the table. 2. Fraction Decimal Percent 7 ᎏᎏ 10 3 ᎏᎏ 8 0.7 0.375 1 ᎏᎏ 3 0.3 70% 38% 33% Mixed Practice Math Boxes in this lesson are paired with Math Boxes in Lesson 5-8. The skill in Problem 6 previews Unit 6 content. — Estimate an answer for each problem. Sample answers: a. 20.6 ⫼ 4 Estimate b. 184.38 ⫼ 9 Estimate c. 15.503 ⫼ 7 Estimate d. 872.16 ⫼ 8 Estimate 83 89 90 3. Ongoing Assessment: Recognizing Student Achievement Math Boxes Problem 5 Use Math Boxes, Problem 5 to assess students’ ability to compare fractions. Students are making adequate progress if they write the fractions correctly from least to greatest. [Number and Numeration Goal 6] T F F 2 ⫽ 64 F 兹99 苶⫽9 3.5 ⬎ 0.35 2 b. ᎏᎏ 5 0.560 c. 0.099 d. 0.099 , 0.19 , 0.204 , 0.265 , 0.560 1 3 ⬍ ᎏᎏ 4 32 33 夹 9 32 66 Put the following fractions in order from least to greatest. , 3 ᎏᎏ 8 , 2 ᎏᎏ 3 , 4 ᎏᎏ 5 , 6. 9 ᎏᎏ 10 INDEPENDENT ACTIVITY (Math Masters, p. 139) Determine whether the following sentences are true or false. Write T or F. a. 0.265 1 ᎏᎏ 4 4. 0.19 3 4 2 1 9 ᎏᎏ, ᎏᎏ, ᎏᎏ, ᎏᎏ, ᎏᎏ 8 5 3 4 10 Study Link 5 6 42 247–249 Put the following decimals in order from least to greatest. 0.204 5. 5 20 2 108 Circle the letters for the pairs of equivalent fractions. a. 1 3 ᎏᎏ, ᎏᎏ 6 6 b. 15 3 ᎏᎏ, ᎏᎏ 25 5 c. 2 6 ᎏᎏ, ᎏᎏ 3 10 d. 2 10 ᎏᎏ, ᎏᎏ 7 35 e. 48 6 ᎏᎏ, ᎏᎏ 56 7 f. 4 65 ᎏᎏ, ᎏᎏ 9 135 59–61 66 67 Math Journal 1, p. 144 Home Connection Students practice converting between decimals, fractions, and mixed numbers. Study Link Master 䉬 1. Games Decimals, Fractions, and Mixed Numbers Convert each decimal measurement to a mixed number. Longest Road and Rail Tunnels in the U.S. Decimal Length Number Top-It 63 83 89 Mixed-Number Length 79 Cascade Tunnel (Washington) 7.79 miles ᎏ 7ᎏ 100 Flathead Tunnel (Montana) 7.78 miles ᎏ, or 7ᎏᎏ 7ᎏ 100 50 miles Moffat Tunnel (Colorado) 6.21 miles 21 ᎏ 6ᎏ 1 00 miles Hoosac Tunnel (Massachusetts) 4.7 miles 78 BART Transbay Tubes (San Francisco, CA) miles 39 7 10 4 ᎏᎏ 6 3 ᎏᎏ, 10 3.6 miles or miles 3 3 ᎏᎏ 5 miles Source: The Top 10 of Everything 2005 2. The longest one-word name of any place in America is Chargoggagoggmanchauggagoggchaubunagungamaugg. Materials 䊐 number cards 0–9 (4 of each) 䊐 1 Place-Value Mat (Decimals) (Math Masters, p. 493) Players 2 or more Skill Place value for decimals Object of the game To make the largest 3-digit decimal numbers. Directions 1. This game is played the same as Number Top-It (7-Digit Numbers). The only difference is that players use a placevalue mat for decimals. 2. Players take turns turning over the top card from the deck and placing it on any of their empty boxes. Each player takes 3 turns, and places 3 cards on his or her row of the game mat. 3. Players play 5 rounds for a game. Shuffle the deck between each round. The player with the smallest total number of points at the end of the 5 rounds wins the game. Phil and Claire played Number Top-It using the place-value mat for decimals. Here is the result. This name for a lake near Webster, Massachusetts, is 45 letters long. It is a Native American name that means “You fish on your side, I’ll fish on mine, and no one fishes in the middle.” Use this word to answer the problems below. c. 3. What fraction of the word is made up of the letter a? What fraction of the word is made up of the letter c? 15 ᎏᎏ, 45 9 ᎏᎏ, 45 3 ᎏᎏ, 45 or or or – 1 ᎏᎏ ⫽ 0.3 3 1 ᎏᎏ ⫽ 0.2 5 – 1 ᎏᎏ ⫽ 0.06 15 In the space above, write the decimal equivalents for the fractions in Problem 2. Place-Value Mat (Decimals) Phil Ones . 0 . 3 . 6 Tenths Hundredths Thousandths 5 Claire 0 8 4 6 b. What fraction of the word is made up of the letter g? 3 a. (3-Place Decimals) 2 4 56 2 STUDY LINK Student Page Time 5 Date 8 Name Claire’s number is larger than Phil’s number. So Claire scores 1 point for this round, and Phil scores 2 points. Practice 4. 10冄7 苶,1 苶4 苶6 苶→ 714 R6 5. 10冄苶苶 8苶4 苶→ Math Masters, p. 139 8 R4 6. 10冄苶6 苶7 苶5 苶→ 67 R5 Student Reference Book, p. 327 Lesson 5 6 323 Teaching Master Name Date LESSON Time 3 Differentiation Options Fractions and Decimals 56 䉬 Write the fraction name and decimal name for the shaded portion of each square. Use your transparent 100-grid to check your answer. For Problem 9, color the grid to show a fraction and then write the fraction and decimal name for the shaded portion of the square. 1. 3. 2. READINESS Playing Number Top-It 3 10 — — — — — — — — — — — — — — ⫽ 0. 7 20 3 — — — — — — — — — — — — — — 4. ⫽ 0. 5. 40 100 — — — — — — — — — — — — — — ⫽ 0. — — — — — — — — — — — — — — 7. ⫽ 0. 8 100 ⫽ 0. 4 — — — — — — — — — — — — — — ⫽ 0. 1 9. 28.5 100 08 ⫽ 0. — — — — — — — — — — — — — — ⫽ 0. 285 15–30 Min (3-Place Decimals) (Student Reference Book, p. 327) 10 100 6 8. — — — — — — — — — — — — — — — — — — — — — — — — — — — — 6. 6 10 4 2 5 35 PARTNER ACTIVITY To provide experience with decimal place value and ordering decimals, have students play Number Top-It (3-Place Decimals). See Student Reference Book, page 327 for directions. After playing the game, have students choose two decimals from their record sheet and write them using number names. Answers vary. — — — — — — — — — — — — — — ⫽ 0. Math Masters, p. 140 ENRICHMENT Writing Fraction and PARTNER ACTIVITY 15–30 Min Decimal Equivalents for a Shaded 100-Grid (Math Masters, pp. 140 and 141) To apply students’ understanding of fractions and decimals, have them complete Math Masters, page 140. Distribute the transparent 100-grids. Students write the fraction and decimal names for the shaded portions of squares and use a transparent 100-grid to check their answers. Students then shade a copy of Math Masters, page 141 to create their own designs and estimate the fraction and decimal names for the shaded portions. Have students copy their favorite design from Problem 9 and display their designs in the Fractions, Decimals, and Percents Museum. Teaching Master Name LESSON 56 䉬 Date Time 100-Grids EXTRA PRACTICE 5-Minute Math SMALL-GROUP ACTIVITY 5–15 Min To offer students more experience with comparing fractions, decimals, and percentages, see 5-Minute Math, page 93. Math Masters, p. 141 324 Unit 5 Fractions, Decimals, and Percents