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What are we going to do?

Fraction. numerator. 2. 3. Learning Objective. denominator. We will subtract fractions with unlike denominators. What are we going to do?. CFU. Activate Prior Knowledge. The least common denominator ( LCD ) is the lowest multiple shared by a set of denominators.

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What are we going to do?

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  1. Fraction numerator 2 3 Learning Objective denominator We will subtract fractions with unlike denominators. What are we going to do? CFU Activate Prior Knowledge The least common denominator(LCD) is the lowest multiple shared by a set of denominators. Find the least common denominator of the fractions below. 2. 1. 5: 5, 10, 15, 20 Students, you already know how to find the least common denominator of fractions. Now, we will use that skill to subtract fractions with unlike denominators. Make Connection 2: 2, 4, 6, 8, 10 2: 2, 4, 6, 8 3: 3, 6, 9, 12 The LCD of and is 3. The LCD of and is 10.

  2. Fraction numerator Concept Development 2 3 denominator • Fractions with unlikedenominators have a different number of equal parts. • Fractions with likedenominators have the same number of equal parts. • To subtract fractions, both fractions must have likedenominators. • To subtract fractions with unlike denominatorsuse the least common denominator (LCD) to create equivalent fractionswithlike denominators. CFU Which pair of fractions is ready to be subtracted? How do you know? A B In your own words, how do you subtract fractions with unlike denominators? “To subtract fractions with unlike denominators ________.” Subtracting Fractions with Unlike Denominators - - = = 1 3 1 5 6 10 10 10 5 2 - = TheLCDof is10. and × × = = 3 6 1 2 5 3 1 5 10 5 10 2 2 5 5 2 Equivalent Fractions 2 5 1 3 2 3 2 3

  3. Skill Development/Guided Practice To subtract fractions, both fractions must have likedenominators. How did I/you find the least common denominator? How did I/you create equivalent fractions? How did I/you subtract fractions? CFU Subtract fractions with unlike denominators. 2 Find the least common denominator. Hint: Find the lowest shared multiple. Create equivalent1 fractions with like denominators. Hint: Use the least common denominator. Subtract fractions. Hint: Subtract the numerators, keep the denominators the same. Reduce the difference2, if possible. Interpret3 the difference. “___ minus ____ equals ____.” 1 2 3 3 4 4 a 5 1. 2. 2: 2, 4, 6, 8 2: 2, 4, 6, 8, 10 × × 3: 3, 6, 9, 12 5: 5, 10, 15, 20 × × 4. 3. 8: 8, 16, 24, 32 4: 4, 8, 12, 16 × 6: 6, 12, 18, 24 × 12: 12, 24, 36, 48 1 equal value 2 answer to a subtraction problem 3 explain Vocabulary × ×

  4. Skill Development/Guided Practice (continued) How did I/you determine what the question is asking? How did I/you determine the math concept required? How did I/you determine the relevant information? How did I/you solve and interpret the problem? How did I/you check the reasonableness of the answer? CFU 1 2 3 required = needed relevant = has to do with problem reasonableness = possible 4 5 5. Sherry bought of a pound of milk chocolate and of a pound of white chocolate. How much more milk chocolate than white chocolate does Sherry have? 4: 4, 8, 12, 16 × × 2: 2, 4, 6, 8 Sherry bought ____ of a pound more ______________ than _______________. milk chocolate white chocolate 6. Tom bought of a pound of cauliflower and of a pound of celery. How much more cauliflower than celery did he buy? 3: 3, 6, 9, 12, 15 × × 5: 5, 10, 15, 20 Tom bought ____ of a pound more __________ than ___________. cauliflower celery

  5. Relevance To subtract fractions, both fractions must have like denominators. Subtracting fractions will help solve real-life problems. 1 of the pie was left over after the party. Erick just ate of the pie. How much pie is left? + = There is of the pie left. + = + = Subtracting fractions will help you do well on tests. 2 Sample Test Question: 53. A B C D CFU Does anyone else have another reason why it is relevant to subtract fractions with unlike denominators? (Pair-Share) Why is it relevant to subtract fractions with unlike denominators? You may give me one of my reasons or one of your own. Which reason is more relevant to you? Why?

  6. A B To subtract fractions, both fractions must have likedenominators. Skill Closure Subtract fractions with unlike denominators. Read the problem and identify fractions, if necessary. (circle) Find the least common denominator. Hint: Find the lowest shared multiple. Create equivalent fractions with like denominators. Hint: Use the least common denominator. Subtract fractions. Hint: Subtract the numerators, keep the denominators the same. Reduce the difference, if possible. Interpret the difference. “___ minus ____ equals ____.” 1 2 3 4 a 5 Word Bank 4: 4, 8, 12, 16 1. × × fractions like/unlike denominator least common denominator equivalent 8: 8, 16, 24, 32 2. Carmen bought of a pound of grapes and of a pound of nectarines. How many more pounds of nectarines than grapes did Carmen buy? 4: 4, 8, 12, 16 × × 2: 2, 4, 6, 8 Carmen bought ____ of a pound more __________ than ___________. grapes nectarines Access Common Core Which pair of fractions is ready to be subtracted? Explain your answer. Summary Closure What did you learn today about subtracting fractions with unlike denominators? (Pair-Share) Use words from the word bank.

  7. Independent Practice To subtract fractions, both fractions must have likedenominators. Subtract fractions with unlike denominators. Read the problem and identify fractions, if necessary. (circle) Find the least common denominator. Hint: Find the lowest shared multiple. Create equivalent fractions with like denominators. Hint: Use the least common denominator. Subtract fractions. Hint: Subtract the numerators, keep the denominators the same. Reduce the difference, if possible. Interpret the difference. “___ minus ____ equals ____.” 1 2 3 4 a 5 1. 2. 6: 6, 12, 18, 24 8: 8, 16, 24, 32 × × 3: 3, 6, 9, 12 12: 12, 24, 36, 48 × × 3. The Smith family bought a pizza. Jason ate of the pizza and Jamie ate of the pizza. How much more pizza did Jason eat than Jamie? 7: 7, 14, 21, 28, 35 × × 4: 4, 8, 12, 16, 20, 24, 28 _________ ate ____ of a pizza more than _________. Jamie Jason

  8. Periodic Review 1 1. 2. 12: 12, 24, 36 6: 6, 12, 18, 24, 32 × × 4: 4, 8, 12, 16 12: 12, 24, 36, 48 × × 3. Geoff has of a pound of cashews and buys of a pound of pecans. How many more pounds of cashews does he have than pecans? 4: 4, 8, 12, 16 × × 6: 6, 12, 18 Geoff has ____ of a pound more ___________ than __________. cashews pecans Access Common Core Abdul subtracted the fractions below. His teacher, Mrs. Treadwell, says that his answer is incorrect. Explain the mistake that Abdul made.

  9. Periodic Review 2 1. 2. 6: 6, 12, 18, 24 10: 10, 20, 30, 40 × × 8: 8, 16, 24 4: 4, 8, 12, 16, 20 × × Access Common Core Horatio added the fractions below. Some of his answers are incorrect. Circle all the incorrect answers and write the correct solutions.

  10. Periodic Review 3 1. 2. 12: 12, 24, 36 5: 5, 10, 15, 20 × × 4: 4, 8, 12, 16 10: 10, 20, 30 × × Access Common Core Choose Yes or No to show whether each choice is equal to the difference of . Yes No Yes No Yes No Yes No

  11. EDI – Cognitive, Teaching, and English Learner Strategies Cognitive Strategies Teaching Strategies Language Strategies Content Access Strategies

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