Lesson 12-5A Equivalent Fractions and Decimals Common Core Domain Number and Operations—Fractions Cluster Understand decimal notation for fractions, and compare decimal fractions. Standards 4.NF.6 Use decimal notation for fractions with denominators 10 or 100. Also 4.NF.5 Mathematical Practices Make sense of problems and persevere in solving them. ✔Reason abstractly and quantitatively. ✔Construct viable arguments and critique the reasoning of others. Model with mathematics. Use appropriate tools strategically. Attend to precision. Look for and make use of structure. ✔Look for and express regularity in repeated reasoning. Lesson Overview Essential Understanding Objective Students will understand how to use equivalent fractions to write fractions as decimals. Every fraction can be represented by an infinite number of equivalent fractions, but each fraction is represented by the same decimal or an equivalent form. Materials Decimal models (Teaching Tool 24) PROFESSIONAL DEVELOPMENT Math Background Today calculators and computers are so accessible that decimals have become preferred over fractions for reporting and calculating. However, students often find themselves using fractions because they are writing ratios—the number of parts considered to the number of parts in all. Therefore, it is important that students are able to pass back and forth between fraction and decimal representations. In the previous lesson, students wrote decimals equivalent to fractions with powers of 10 as denominators and vice versa. In this lesson, students will write decimals equivalent to 1 Daily Common Core Review Daily Common Core Review not available for this lesson. Consider using additional practice found in the Student Edition as review. 46A Vocabulary fractions with other denominators. Some fractions can be simplified to fractions with denominators that are factors of a power of 10. Once a fraction has been simplified, a fraction equivalent to it can be written with a denominator that is a power of 10. Finally, this fraction can easily be written as a decimal. Students will also encounter fractions that have denominators that are multiples of 10 or 100, that can be changed to become equivalent fractions with a power of 10 as their denominators. Then these fractions can be written as decimals. 2 Develop the Concept: Interactive MATHEMATICAL PRACTICES Problem-Based Interactive Learning 10–15 min Overview Students will use equivalent fractions to write fractions with denominators other than 10 or 100 as decimals. Focus How can you use equivalent fractions to change a fraction to a decimal? Materials Decimal models (Teaching Tool 24) Set the Purpose You have learned to write fractions with denominators of 10 and 100 as decimals. Today, you will learn how to write more fractions as decimals. Connect What does it mean to write a fraction in simplest form? [The numerator and denominator have no common factor other than 1.] Pose the Problem Three fourths of the students in Mr. Brown’s MATHEMATICAL class have a younger brother or sister. How would you write _34 as a PRACTICES decimal? Give students time to work in pairs to solve this problem. Then have them share their thinking. Name Teaching Tool Martise 17 Communicate When students their thinking share with the class, they communicate the thought process they used to write a fraction as a decimal. Whole-Class Discussion Draw three large congruent squares on the board. Use the second square to show tenths and the third square to show a hundredths grid. How could you use the first square to show _34 ? [Divide the square into 4 equal parts and shade 3 parts.] Divide the square into fourths using a horizontal line and a vertical line. Shade 3 fourths. Point to the second square. Is it possible to shade some tenths to show the same amount shaded as in the first square? [No] Point to the third square. Is it possible to shade some hundredths to show the same amount? [Yes] Shade __34 of the hundredths grid. What fraction tells how 75 75 many hundredths are shaded? [ ___ ] Write __34 5 ___ 100 on the board. 100 What decimal tells how many hundredths are shaded? [0.75] Write 75 ___ 100 5 0.75 on the board. Suppose you did not have models to use. How could you have written _34 as an equivalent fraction with a denominator of 100? [Multiply 3 and 4 by 25 to get 75 and 100.] Could you have written _ 34 as an equivalent fraction with a denominator of 10? Explain. [No; You can’t multiply 4 by a whole number to get 10.] 3 _ 4 75 75 ___ ___ 3 _ = 0.75 = 4 100 100 TT 17 SF_TT_04_08 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. 4 2/15/11 1:08 PM M_TET17.indd MTH12_ANC4_TR 17 Small-Group Interaction Work with your partner. Write __ 52 as a decimal. [0.4] 36 36 12 Write ___ 300 as a decimal. Show your thinking. [ ___ 5 ___ 100 5 0.12] 300 eTools Fractions www.pearsonsuccessnet.com 46B 3 Develop the Concept: Visual Equivalent Fractions and Decimals How can you use equivalent fractions to change a fraction to a decimal? A pan of cornbread was divided into 12 equal 6 12 of the pieces, and 6 out of 12 pieces or __ cornbread remains. Write a fraction equivalent 6 12 , and then change the fraction to a decimal. to __ 6 _ In simplest form __ 12 is 1 . Find an equivalent 2 fraction with a denominator of 10. What are equivalent fractions? [Fractions that represent the same amount] How can you write equivalent fractions? [Multiply or divide the numerator and denominator by the same number.] 2 times what number equals 10? 35 5 _ 1 5 __ 10 2 35 _ 1 5 __ 5 2 10 __ 5 is five tenths, or 0.5. 10 So, 0.5 of the cornbread remains. Lesson 12-5A 1 Set the Purpose Call students’ attention to the Visual Learning Bridge at the top of the page. In this lesson, you will learn how to use equivalent fractions to write fractions as decimals. Common Core 4.NF.6 Use decimal notation for fractions with denominators 10 or 100. Also 4.NF.5 Other Examples 3 as a decimal. Write ___ Write 0.8 as a fraction in simplest form. 3 __ In simplest form ___ is 1. 12 4 8 0.8 is eight tenths, or ___ . 10 12 Find an equivalent fraction with a denominator of 100. 8 Simplify the fraction ___ . 10 8 and 10 are multiples of what number? 4 times what number equals 100? 3 25 Explain It Reason Quantitatively Point out to students that, when a problem contains a fraction and a decimal, it is helpful to change one number so that it is in the same form as the other. How could you change _ 12 to a decimal with the same number of decimal places as 0.12? [Find a fraction equivalent to __12 with a denominator of 100.] How could you change 0.12 to a fraction? [Write it as a fraction with a denominator of 100.] How can you use equivalent fractions to change a fraction to a decimal? A pan of cornbread was divided into 12 equal 6 of the pieces, and 6 out of 12 pieces or ___ 12 cornbread remains. Write a fraction equivalent 6 , and then change the fraction to a decimal. to ___ 12 Other Examples Look at the first example. What question could you ask yourself 3 to decide if you first need to change __ 12 to simplest form? [Can I multiply 12 by a number to get 10 or 100?] What is the answer to your question? [No] Could you find a fraction equivalent to _14 that has a denominator of 10? Explain. [No; There is no whole number I can multiply the denominator 4 by to get a denominator of 10.] Equivalent Fractions and Decimals 42 25 1 5 ___ __ 4 8 5 __ ___ 3 25 42 4 100 5 10 25 ___ is twenty-five hundredths, or 0.25. 100 3 So, ___ 5 0.25. 12 4. 0.8 is eight tenths, or __ 5 4. So, 0.8 5 __ 5 Explain It 1. Reason Why is the fraction __12 not written as 0.12? See margin. 2 as an 2. What steps would you take to rename __ 4 equivalent fraction with a denominator of 100? See margin. 46 1. S ample answer: 0.12 5 ____ 12 and __ 1 5 ___ 5 5 ____ 50 . 100 2 10 100 ____ 12 is not equivalent to ____ 50 . MTH12_SE04_CCTK_TPC12_L05A.indd 46 100 100 2. Sample answer: First I would find what number to multiply 4 by to get 100 in the denominator. That number is 25. Then I would multiply the numerator and denominator by 25: 25 3 2 5 50 and 25 3 4 5 100. So __ 2 5 ____ 50 . 4 46 100 7/12/11 MT 3:1 Write _ 34 as a decimal. 6 How do you simplify __ 12 to _ 12 ? [Divide both 6 and 12 by 6.] How do you know that _12 is in simplest form? [The only whole number that you can divide 1 and 2 by is 1.] Multiply to find an equivalent fraction with a denominator of 100. 4 times what number equals 100? 3 25 _ 3 5 ___ 75 4 _ 3 5 ___ 75 4 100 100 3 25 75 ___ is seventy-five hundredths, or 0.75. 100 6 __ In simplest form ___ is 1 . Find an equivalent 12 2 fraction with a denominator of 10. 2 times what number equals 10? 3 Write __ as a decimal. 4 35 4 times what number equals 100? 3 25 5 1 5 ___ __ 2 5 1 5 ___ __ 2 Multiply to find an equivalent fraction with a denominator of 100. 10 3 75 __ 5 ____ 4 35 3 ___ 75 __ 5 2 10 5 ___ is five tenths, or 0.5. 10 4 100 100 100 MATHEMATICAL Guided Practice PRACTICES Do you know HOW? Do you UNDERSTAND? For 1 through 6, write each fraction as a decimal. 7. Write a fraction and an equivalent decimal to show the part of the cornbread that has been eaten. ___ 6or0.5 12 8. Writing to Explain When you write a fraction as a decimal, why do you need to rename the fraction as an equivalent fraction with a denominator of 10 or 100? n 1. __35 5 __ 10 6 50 2. __245 __ 100 1 3. __ 5 0.2 3 4. ___ 12 0.25 2 5. __ 8 0.25 3 6. __ 5 0.6 0.6 n 0.50 n 9. __255 __ 10 4 n n 8 4 5 __ 7 5 ___ n 10. __ 45 5 __ 11. __ 13. ___ 100 12. __28 5 ___ 5 n 10 10 8 100 25 100 7 3 14. __ 12 6 15. ___ 10 0.25 0.8 0.8 4 16. ___ 10 0.6 0.4 0.25 35 18. ___ 100 17. __ 15 0.2or0.20 0.35 19. __48, 0.5 20. __15, 0.15 65 21. ___ , 0.65 100 2 , 0.35 22. __ 4 4 , 0.08 23. __ 8 6 24. ___ , 0.6 12 4 , 0.5 25. __ 8 8 26. ___ , 0.08 100 3 , 0.25 27. ___ 12 3 28. __ , 0.03 10 4 , 0.8 29. __ 5 30. __12, 0.05 Yes No Yes No No No Exercise 3 Error Intervention If students multiply only the numerator or denominator of the fraction by 2, then review with them how to find equivalent fractions. Remember, you must multiply the numerator and the denominator by the same number to write a fraction that has the same value. 48 Reteaching Work together with students to write __ 35 and __ as decimals. Yes Independent Practice For Exercises 19–30, remind students that when deciding if numbers are equivalent, it is helpful to have both numbers written in the same form. Encourage students to write the fractions as decimals. However, keep in mind that some students may choose to write the decimals as fractions. 0.07 In 19 through 30, tell whether each pair shows equivalent numbers. PRACTICES Remind students that when changing a fraction to a decimal, they should first ask themselves if they can multiply the denominator of the fraction to get 10 or 100. If not, encourage them to try simplifying the fraction. 3 In 9 through 18, write each fraction as a decimal. 0.4 MATHEMATICAL Seemargin. Independent Practice Guided Practice 3 25 75 ___ is seventy-five hundredths, or 0.75. So, 0.5 of the cornbread remains. Could you use the same steps to change _ 34 6 to a decimal as you used to change __ 12 to a 3 decimal? Explain. [No; _4 is in simplest form already. Also, the denominator 4 can be multiplied by 25 to get the denominator 100.] 6 Could you use the same steps to change __ 12 3 to a decimal as you used to change _ 4 to a decimal? Explain. [No; There is no whole number I can multiply the denominator 12 by to get the denominator 10 or 100.] No Yes Yes Yes No Lesson 12-5A 47 8.Sample answer: So that the denominator of the fraction is equivalent to the place value of the decimal. TH12_SE04_CCTK_TPC12_L05A.indd 14 AM 47 7/12/11 3:14 AM 47 3 Develop the Concept Problem Solving MATHEMATICAL Students use underlying processes and mathematical tools for Exercises 31–40. Remind students to check for reasonableness when solving each problem. Exercise 31 Language of Math: Everyday Vocabulary The term batting average may be new to students. A batting average tells the number of hits a player usually gets out of a certain number of times at bat. 24 The fraction ___ 100 tells you that Roger usually gets 24 hits out of 100 times at bat. However, sometimes he may get more or less. Point out that batting averages are usually written as a decimal to the nearest thousandth without the 0 to the left of the decimal point. Therefore, the batting average 0.24 or 0.240 would usually be written .240. Exercise 38 Use Bar Diagrams What hidden question do you need to answer before you can solve this problem? [How many days are in 1 week?] How does the bar diagram show the answer to this question? [The bar is divided into 7 parts, and each part represents one day.] Exercise 39 Check for Reasonableness Encourage students to check the answer they choose for reasonableness. Visualize _45 of a shape shaded. About how much of the shape is shaded: a little less than half, a little more than half, or almost the whole shape? [Almost the whole shape] Is the value of the decimal you chose close to 1 whole? [Yes] Early Finishers Have students write and solve a comparison problem similar to Exercise 33 that is about a class of 25 fourth graders. Have students explain how they can use equivalent 8 fractions to change a fraction to a decimal, using ___ 100 and __ 48 as examples. MATHEMATICAL Problem Solving PRACTICES 31. Roger got 24 hits out of 100 times at bat. What is his batting average as a fraction in simplest form? Then write an equivalent decimal. ___ 6;0.24 25 32. Critique Reasoning The model below represents 1 whole. Maura says that the shaded part of the model 70 5 0.07. Is Maura shows that ___ 100 correct? Explain why or why not. Seemargin. PRACTICES BattingAverage5 Numberofhits Numberoftimesatbat 33. A band has 20 instruments. Tyler says that __25 of the instruments are string instruments and 0.5 of the instruments are wind instruments. Does the band have the same number of wind instruments and string instruments? Explain. Seemargin. 34. Gina wrote a 4-digit number. She used each of the digits 1, 3, 5, and 7 once. How many different 4-digit numbers can Gina write? 35. Writing to Explain Which is greater, 3 __ or 0.75? Explain your answer. 4 __ 3isequivalentto____ 75,and____ 7550.75. 4 100 100 36. Reason The cell phone was invented in Sweden in 1979. How many years ago was the cell phone invented? 37. Write a fraction in simplest form and an equivalent decimal to show what part of a dollar 5 cents represents. (Hint: 1 dollar 5 100 cents.) ___ 1;0.05 20 24numbers Answerfor2011:32years For 38, use the diagram at the right. 0.755 0.75.Thenumbersareequal. ?newspapersinall 38. Kwan has 37 customers on his paper route. He delivers newspapers every day. How many newspapers does he deliver in one week? 37 259newspapers 39. Reasonableness Betty’s score on 4. a 5-point quiz was 4 out of 5, or __ 5 What is __45 written as a decimal? 37 37 37 37 37 Newspapersdelivered eachday 40. Nine of the 12 students in the school play are fourth graders. Which decimal represents the part of the students that are fourth graders? A 0.4 B 0.45 A 0.25 C 0.6 B 0.6 D 0.8 C 0.75 D 0.9 Journal 37 48 32. Maura is not correct; Sample answer: The grid shows ____ 70 or 0.7. To show 0.07, only 7 small squares should be 100 shaded. MTH12_SE04_CCTK_TPC12_L05A.indd 48 2 written as a decimal is 0.4. 33. N o; Sample answer: __ 5 0.4 0.5, so the band has fewer string instruments than wind instruments. 48 7/12/11 MT 3:1 Solve each equation for z. 1. z 1 22 5 24 2. z 2 19 5 24 3. z 3 4 5 32 4. z 4 9 5 4 5. 15 1 z 5 24 6. z 2 22 5 22 7. 6 3 z 5 6 8. z 4 5 5 1 9. 3 3 z 5 18 z52 z543 z536 z58 z59 z51 z544 z55 Exercises 1–9 Reteaching Students may have difficulty remembering to work backward to solve the problem. Have them write out the problem in word form and how to solve the problem in word form. Use Exercise 8 as an example. Students should say z divided by 5 equals 1 and ask what divided by 5 equals 1. Remind them to work backward from there. Ask students what they need to do to both sides of the equation to isolate z. z56 Round each decimal to the nearest tenth. 10. 9.64 9.6 11. 1.05 12. 3.52 1.1 13. 16.67 3.5 14. 87.24 16.7 87.2 Find the sum. Estimate to check if the answer is reasonable. 15. 9 1 3,529 1 27 1 621 4,186 16. 17,868 1 913 1 2,781 21,562 18. 2 1 129 1 56 1 374 17. 475 1 25 1 5,350 1 25,275 31,125 561 Reason Find each value of w that is not correct. Write it correctly, and explain the error. 19. 20 1 w 5 68 w 5 88 Seemargin. 20. w 2 12 5 50 w 5 62 Correct 21. w 4 2 5 9 w 5 11 22. w 3 6 5 42 w58 Seemargin. w57;Divided incorrectly. Number Sense Construct Arguments Write whether each statement is true or false. Explain your answer. 23. The expression 101 2 25 equals 76. True;101225510022511or7511576. 24. The product of 4 and 682 is closer to 2,400 than 2,800. False;43682isabout4370052,800. 25. The sum of 251 and 173 is less than 400. False;Thesumof251and173isabout25011705420,and420.400. 26. The quotient of 0 divided by 1 is 1. True;Usingmentalmath,53405200,535525,and2001255225. 28. The difference of 844 and 172 is greater than 600. True;Thedifferenceisgreaterthan80022005600. Lesson 12-5A Exercises 19–22 Reason Quantitatively Discuss with students common errors they can make when solving equations. Remind students to look closely at the operation in each equation and decide if the given value for the variable is correct. Number Sense False;Thequotientof0dividedbyanynonzeronumberisalways0. 27. The product of 5 and 45 is 25 more than 200. Exercises 10–14 Students can extend previous knowledge about rounding numbers to the tens and hundreds place when working on these exercises. What place value do you use when rounding a number to the hundreds place? [Tens] What place value will you use when rounding a decimal to the tenths place? [Hundredths] 49 Exercise 27 Point out that this exercise is different from the others because it requires the use of two operations. Remind students that the word is separates the two quantities they are checking for equality. What expression represents the quantity to the left of is? [5 3 45] What expression represents the quantity to the right of is? [200 1 25] 19. w 5 88 is incorrect. The correct solution is w 5 48; Found the sum of 68 and 20 instead of the difference. 21. w 5 11 is incorrect. The correct solution is w 5 18; Found the sum of 9 and 2 instead of the product. TH12_SE04_CCTK_TPC12_L05A.indd 49 13 AM 7/12/11 3:13 AM 49 4 Close/Assess and Differentiate Close Essential Understanding Every fraction can be represented by an infinite number of equivalent fractions, but each fraction is represented by the same decimal or an equivalent form. In this lesson, you learned how to use equivalent fractions to change a fraction to a decimal. ASSESSMENT Quick Check Master Quick Check Name Exercises 1–4 are worth 1 point each. Use the rubric to score Exercise 5. 12-5A 3 as a decimal? 1. Which shows __ 12 2.Which shows a pair of equivalent numbers? A 0.025 16 ; 0.8 A __ 20 B 0.25 Exercise 5 25 ; 0.4 B ___ 100 C 0.312 D 0.35 9 as a decimal? 3. Which shows __ 20 C 6 ; 0.68 __ D 0.75 8 3; __ 5 Writing to Explain Students should explain why they must first simplify __ 36 to __ 12 and then write an equivalent fraction with a denominator that is equivalent to a decimal place value. 4.Which shows a pair of equivalent numbers? A 0.92 4 ; 0.45 __ 5 3 ; 0.3 B ___ 100 A B 0.55 C 0.45 15 ; 0.8 C __ 20 D 0.092 3 D ___ ; 0.06 Model Thinking Aloud Help students verbalize what they are thinking. Say, To change a fraction to a decimal, I need a fraction with a denominator of 10 or 100. I notice that the denominator of _ 63 is 6. 50 5.WritingtoExplain When writing __36 as a decimal, why do you 5? first need to rename the fraction as __1 and then as __ 2 10 Seestudentsamplestotheright. Q 12•5A Student Samples 3-point answer The student correctly explains why he or she must first simplify __ 36 and then writes an equivalent fraction with a denominator that is equivalent to a decimal place value. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. 4 MTH12_ANC4_TRM_Q12-05a.indd 31 Formative Assessment Use the Quick Check to assess students’ understanding. 6 by _3 I can’t multiply or of 6 is 6. at in m no st I de fir he So T 100. r to get 10, or 1 be m _ nu le ho w . any 3 rm. That’s 2 _ in simplest fo or need to write 6 and denomin5at the numerator __ . The I can multiply n tio lent frac 5 10 1 _ get the equiva __ the of 2 by 5 to n write 10 as tenths, so I ca s ow sh n tio frac decimal 0.5. 7/14/11 8:37 PM 2-point answer The student correctly shows changing __ 36 to a decimal but does not explain why the steps are necessary. ÷ 3 × 5 6_3 = 2_1 = __5 = 0.5 10 ÷3 ×5 1-point answer The student demonstrates little or no understanding of how to change a fraction to a decimal. 5 __ 1 3 _ _6 = 2 = 10 Prescription for Differentiated Instruction Use student work on the Quick Check to prescribe differentiated instruction. 49A Points Prescription 0–4 Intervention 5–6 On-Level 7 Advanced Differentiated Instruction Intervention On-Level Advanced Par tner Par tner Talk Equivalent Fractions and Decimals Sh 70 0 100 •Remind students that one way to write an equivalent fraction is to multiply the numerator and denominator by the same number. •You can write a fraction with a denominator of 10 as a decimal. What denominators can be multiplied by a number to get an equivalent fraction with a denominator of 10? [2, 5] Make a list as students name the denominators. Work together to 5 change __12 to __ to 0.5. 10 Get Started or 0 0.90 1 0.5 2 0.75 3 0.3 4 0.15 5 0.6 6 0.8 7 0.25 8 0.2 9 0.4 2 3 10 20 4 3 5 5 2 5 6 3 4 7 7 100 9 1 4 One Whole One Whole 0.4 0.05 0.8 0.07 0.6 3 4 6 20 1 4 3 5 4 5 0.5 0.25 0.7 0.9 0.75 1 5 9 10 3 20 2 5 1 2 Take turns. Say any fraction that has 10 in the denominator. Your partner explains how to show that fraction on the grid and says an equivalent decimal in hundredths. If you have more time Center Activity H 12-5A • Repeat for hundredths. Have students name a few denominators for hundredths. k. are wor your t hinking while you Pick a number tile to find a decimal. Say that decimal. Explain how to show that decimal on the whole grid with 100 parts. Explain how to find an equivalent fraction. Cover the equivalent fraction with your number tile. Display each 0–9 tile exactly once. If you have a partner, take turns. 1 1 20 4 5 90 8 100 Sh k. are wor your t hinking while you Pick a number tile to find a fraction. Say the fraction. Explain how to show that fraction on the whole grid with 100 parts. Explain how to find the equivalent decimal. Cover the equivalent decimal with your number tile. Display each 0–9 tile exactly once. If you have a partner, take turns. Get Started or 10–15 min Talk If you have more time Try again. This time say the equivalent fraction in the grid and another equivalent fraction for each decimal. Center Activity HH 12-5A Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. 4 MTH12_ANC4_TRM_CA12-05a.indd 3 7/14/11 4:47 PM Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. 4 MTH12_ANC4_TRM_CA12-05a.indd 4 7/14/11 4:48 PM : Partner Talk Listen for names of equivalent decimals. For example, a student might say, “Two tenths is equivalent to twenty hundredths because there are ten hundredths in every tenth.” Leveled Homework Reteaching Master Practice Master Reteaching Name Name 12-5A Equivalent Fractions and Decimals 6 1 ___ = __ 12 2 2 ×5 10 100 25 0.25 9 2. ___ 5 ____ 20 45 100 2 ; 0.5 6. __ 5 15 10 5; 2 0.2 0.8 50 0.08 25 100 32 5 0.32 12. Which decimal is equivalent to ___ 5 ? 20 4 7. ___ 25 0.16 13 8. ___ 20 0.65 9 9. ___ 50 0.18 Tell whether each pair shows equivalent numbers. No Yes No R 12•5A MTH12_ANC4_TRM_R12-05a.indd 32 0.95 0.46 A 0.20 C 0.35 B 0.25 D 0.52 4 ; 0.25 8. ___ 16 3 ; 0.75 __ 0.6 16 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. 4 50 Yes 7/14/11 9:47 PM eTools Fractions www.pearsonsuccessnet.com MTH12_ANC4_TRM_P12-05a.indd 33 5 4. 3. 11. Kevin has 20 words to learn for his spelling test on Friday. He has learned 6 of the words. So, he has learned ___ 6 of the 20 6 in simplest form, words. Write ___ 20 and find an equivalent decimal. 1 ; 0.25 __ 1 ; 0.25 __ 4 4 3 ; 0.3 ___ 6. 5. 10 13. Gina wrote that __ 45 is greater than 0.75. Is Gina correct? Explain why or why not. 1 ; 0.5 __ 3 ; 0.6 __ 2 4 ∙ 0.8 and Yes; __ 5 0.8 > 0.75. P 12•5a 2 ; 0.4 __ 4 11 ; 0.22 9. ___ Yes 2. 1. 50 5 Shade some parts of each shape below. Write a fraction in simplest form and a decimal to represent the shaded part of the shape. 7. 4 as __ 1. Sample answer: I renamed ___ 4 16 Next, I multiplied the numerator and 25 25 1 __ ____ ____ denominator by 25: ∙ . ∙ 0.25, 4 100 100 4 ∙ 0.25. so ___ Yes 9 14. Nine out of 15, or ___ , of the people at the skating rink brought their own 15 9 . skates. Write an equivalent decimal for ___ 15 Write a fraction in simplest form and a decimal for the shaded part of each shape. 23 5. ___ 14. Look at Exercise 8. Explain how you decided whether the numbers are equivalent. 10 3 7 ; 0.35 2 ; 0.25 11. ___ 10. __ ; 0.4 12. __ ; 0.35 13. ___ 5 5 25 20 No 2 ∙ 0.4 Yes; __ Write each fraction as a decimal. 4 6. ___ 4 5. __ 5 20 10. A rock band has 5 members, 2 of the members play and __ 5 string instruments. Also, 0.4 of the members sing. Does the band have the same number of string instrument players as singers? Explain. 8 4. ___ 5 ____ 20 0.44 7 ; 0.07 7. ___ No 12 3 1 ___ 3. ___ 5 5 ___ 0.45 0.75 25 In 6 through 9, tell whether each pair shows equivalent numbers. In 1 through 4, find the missing numbers. Then write each fraction as a decimal. 4 19 4. ___ 11 3. ___ 12 0.2 Step 2 Rename the fraction Step 3 Write the decimal. using a denominator of 10, ___ 5 is five tenths. 100, or 1,000. 10 5 ___ = 0.5 ×5 Think: What 10 5 1 __ = ___ number times 6 So, ___ = 0.5 2 equals 10? 1 1. __ 5 ____ 9 2. ___ 1 1. __ 5 12 12-5A Visualize Fractions and Decimals In 1 through 5, write each fraction as a decimal. 6 Write ___ as a decimal. Enrichment Name 12-5a Equivalent Fractions and Decimals A fraction and a decimal can both be used to represent the same value. Step 1 Write the fraction in simplest form. Enrichment Master Practice 8. Answers may vary. Check students’ Answers may vary. Check students’ work. work. E 12•5A Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. 4 7/14/11 6:09 PM eTools Fractions www.pearsonsuccessnet.com MTH12_ANC4_TRM_E12-05a.indd 34 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. 4 7/14/11 5:35 PM eTools Fractions www.pearsonsuccessnet.com 49B
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