Moving with Algebra Sampler

23 Change Fractions to Decimals Decimals Changing fractions to decimals when the denominator is a factor of 10 or 100 Lesson Plans 140 ©MathTeachersPress, Inc. Reproduction by anymeans is strictly prohibited. 52 Changing Fraction to Decimal :Denominator i a Factor of 10 or 100 Change todecimal by fir t renamingeach fractionwithadenominatorof10or100. 3 5 1. 1 4 2. 1 2 3. 1 5 4. 3 20 5. 4 5 6. 4 25 7. 7 50 . 2 5 9. 9 20 10. 11 25 11. 14 50 12. 14. Which of these fractions have denominatorswhich can be divided evenly into 10? 15. Which of these fractionshave denominatorswhich can be divided evenly into 100? TeamAwon 3 out of 4 baseball games.TeamBwon 4 out of 5 baseball games.Which team had the better record?Explain inwords and symbols how you know. 13. Which of these numbers divide evenly into 10 or 100?Write “no”, “10”and/or “100” in each blank. 2 _______ 3 _______ 4 _______ 5 _______ 8 _______ 10 _______ 12 _______ 15 _______ 20 _______ 25 _______ 40 _______ 50 _______ 1. Ludviko falis tre forte. Multaj katoj acxetis la vere bona vojo.Kolorado igxis dumalbona bildoj. _____________________ 2. Nau stulta auxtoj malvarme pripensis tri tre eta katoj.La radioj malbele igxis tri cxambroj. _____________________ 3. Kvar flava katoj gajnas tri vere rapida auxtoj.Ses malbona libroj saltas, sed kvin birdoj blinde skribas. _____________________ 4. sedmultaj flava vojoj acxetis du alrapida kalkiloj, kaj nau cxambroj. _____________________ 5. Multaj alrapida hundoj gajnas nau veremalbona kalkuliloj. _____________________ Nau vere bona. Name ___________________________ Jenny 6. kaj kvin auxtoj saltas, sed ses stulta tratojmalbele acxetis du arboj. _____________________ 7. Nau bona arboj parolis. Multaj domoj pripensis tri tremalpura katoj. _____________________ . Kolorado varme gajnas se bieroj.Du bela cambroj trinkis nau alta birdoj. _____________________ 9. Ludviko saltas tre al rapide, kaj la vere bona bildoj skribasmultaj tre. _____________________ 10. kaj kvin libroj batos kvar birdoj, sed Londono stulte gajnas lamalbona kato. _____________________ La biero falis, kaj. Kvin telefonoj tre. Ses domoj. Kvar alrapida. Multaj katoj helfis. Kvin stulta auxtoj. Tri telefonoj. Kvin kalkuliloj falis. Nau klara vojoj. QUIZ 1 9 0 ___ ___ 100 46 50 = 100 9 10 = Jenny scored higher on the (quiz, test). ____________ 1. 2. 3. 4. 5. 6. 7. . 9. 10. 11. 12. 13. 14. 15. 16. 17. 1. 19. 20. 21. 22. 23. 24. 25. Name___________________________ Jenny 26. 27. 2. 29. 30. 31. 32. 33. 34. 35. 36. 37. 3. 39. 40. 41. 42. 43. 44. 45. 46. 47. 4. 49. 50. TEST 4 5 6 0 nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer nswer To change a fractionto a decimal, the denominatormust be 10 or 100 or 1000, etc.Both of these fractions can be changed to hundredths. Jenny got 9 out of 10 questions correct on her Latin quiz.Aweek later, she took a test and got 46 out of 50 correct.Did Jenny score higher on the quiz or on the test? = ? 100 9 10 = ? 100 46 50 Multiply bothterms by the same number. 10,100 no 100 10,100 no 10,100 no 100 100 100 no no Test 10 2 92 90 6 10 0.6 25 100 0.25 5 10 0.5 2 10 0.2 15 100 0.15 8 10 0.8 16 100 0.16 14 100 0.14 4 10 0.4 45 100 0.45 44 100 0.44 28 100 0.28 Objective: To change fractions to decimals when the denominator is a factor of 10 or 100. Materials: Interlocking cubes Factors of 10 and 100 from Arrays Each small group will need at least 10 interlocking cubes and the class will need at least 100 interlocking cubes. Use 10 cubes to build all the different rectangles you can. How many different rectangles can you build? (2) Ask a volunteer to draw a picture of the two different rectangles on the board: The sides of the rectangles are the factors of 10. What are the factors of 10? (2, 5, 1, 10) Repeat the activity with the whole class, this time using 100 cubes. The rectangles that can be built are 2 50, 4 25, 5 20, 10 10, and 100 1. What are the factors of 100? (1, 2, 5, 10, 20, 25, 50, and 100) Changing Fractions to Decimals: Denominator is a Factor of 10 or 100 Can we change 3 ⁄ 4 to an equivalent fraction with a denominator of 10? (No.) Can we change 3 ⁄ 4 to an equivalent fraction with a denominator of 100 … is 4 a factor of 100? (Yes.) Write on the board: Write on the board: Change each fraction to an equivalent fraction with a denominator of 10 or 100. Then change each fraction to a decimal in tenths or hundredths. 2 5 2 7 0 2 1 5 1 5 2 0 1 How can we change 2 ⁄ 5 to an equivalent fraction with a denominator of 10 or 100? (Multiply both terms by 2 to change the fraction to tenths.) 3 4 75 100 = 75 100 = x 25 x 25 0.75 Write on the board: How do we write 4 ⁄ 10 as a decimal? (0.4) Continue: Read the example together at the top of the page. Emphasize that fractions must have the same denominators before they can be compared. Work problems 1, 5, 6 and 8 together. Students may complete the page on their own. Skill Builders p. 115 7 20 35 100 = x 5 x 5 11 25 44 100 = x 4 x 4 21 50 42 100 = x 2 x 2 2 5 4 10 = x 2 x 2 Sample Lesson Sample Scripting (Bold Type) ©M Reproduction 52 Changing Fraction to Deci Change to decimal by fir t renam 3 5 1. 1 4 2. 3 20 5. 4 5 6. 2 5 9. 9 20 10. 14. Which of these fractions have de 15. Which of these fractionshave den Team A won 3 out of 4 b games.Which team had t how you know. 13. Which of these numbers divide in each blank. 2 _______ 3 _______ 4 12 _______ 15 _______ 20 To change a fraction to a decimal the denominatormust be 10 or 10 or 1000, etc. Both of these fractio can be changed to hundredths. Jenny got 9 out of 10 questions correct on her Latin quiz.A week later, she took a test and got 46 out of 50 correct.Did Jenny score higher on the quiz or on the test? = ? 100 9 10 = ? 100 46 50 10,100 no no no 6 10 0.6 25 100 15 100 0.15 8 10 4 10 0.4 45 100 Objective: To change fractions to decimals when the denominator is a factor of 10 or 100. Materials: Interlocking cubes Factors of 10 and 100 from Arrays Each small group will need at least 10 interlocking cubes and the class will need at least 100 i terlocking cubes. Use 10 cubes to build all the different rectangles you can. How many different rectangles can you build? (2) Ask a volunteer to draw a picture of the two different rectangles on the board: The sides of the rectangles are the factors of 10. What are the factors of 10? (2, 5, 1, 10) Repeat the activity with the whole class, this time using 100 cubes. The rectangles that can be built are 2 50, 4 25, 5 20, 10 10, and 100 1. What are the factors of 100? (1, 2, 5, 10, 20, 25, 50, and 100) Changing Frac ions to Decimals: Denominator is a Factor of 10 or 100 Can we change 3 ⁄ 4 to an equivalent fraction with a denominator of 10? (No.) Can we change 3 ⁄ 4 to an equivalent fraction with a denominator of 100 … is 4 a factor of 100? (Yes.) Write on the board: Write on the board: Change each fraction to an equivalent fraction with a denominator of 10 or 100. Then change each fraction to a decimal in tenths or hundredths. 3 4 75 100 = 75 100 = x 25 x 25 0.75 Write on the board How do we write Continue: Read the example page. Emphasize that 7 20 11 25 21 50 2 5 Decimals & Percents Unit 3