5 th Grade Number Sense 2.3 (5Q) Solve simple problems, including ones arising in concrete situations, involving the addition and subtraction of fractions and mixed numbers (like and unlike denominators of 20 or less), and express answers in the simplest form. Lesson to be used by EDI-trained teachers only. DataWORKS Educational Research (800) ©2012 All rights reserved. Comments? Learning Objective Name __________________________ Today, we will subtract fractions with unlike denominators. CFU What are we going to do today? Activate (or provide) Prior Knowledge A fraction is a number that represents part of a whole. CFU Students, you already know how to subtract fractions with like denominators. Today, we will subtract fractions with unlike denominators. Subtract fractions with like denominators. Hint: Subtract numerators and keep the denominators the same. 3 4 numerator denominator Fraction Fractions with like denominators have the same number of equal parts.

5 th Grade Number Sense 2.3 (5Q) Solve simple problems, including ones arising in concrete situations, involving the addition and subtraction of fractions and mixed numbers (like and unlike denominators of 20 or less), and express answers in the simplest form. Lesson to be used by EDI-trained teachers only. DataWORKS Educational Research (800) ©2012 All rights reserved. Comments? Concept Development Fractions with unlike denominators have a different number of equal parts. To subtract fractions, both fractions must have like denominators. To subtract fractions with unlike denominators use the least common denominator (LCD) to create equivalent 1 fractions. The least common denominator (LCD) is the lowest multiple shared by a set of denominators. 1 equal value Subtracting Fractions with Unlike Denominators    Equivalent Fractions 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 __________. 3 5 The LCD of and 1 2 is × 6 10 = × 5 =

5 th Grade Number Sense 2.3 (5Q) Solve simple problems, including ones arising in concrete situations, involving the addition and subtraction of fractions and mixed numbers (like and unlike denominators of 20 or less), and express answers in the simplest form. Lesson to be used by EDI-trained teachers only. DataWORKS Educational Research (800) ©2012 All rights reserved. Comments? Subtract fractions with unlike denominators. Step #1: Read the problem and identify 2 fractions, if necessary. (circle) Step #2: Find the least common denominator. Hint: Find the lowest shared multiple. Step #3: Create equivalent fractions. Hint: Use the least common denominator. Step #4: Subtract fractions. Hint: Subtract the numerators, keep the denominators the same. a. Reduce the difference 3, if possible. Step #5: Interpret 4 the difference. 2 find 3 answer to a subtraction problem 4 explain To subtract fractions, both fractions must have like denominators. Skill Development/Guided Practice CFU (#2) How did I/you find the least common denominator? (#3) How did I/you create equivalent fractions? (#4) How did I/you subtract fractions? 2: 2, 4, 6, : 3, 6, 9, 12 × × 2. 2: 2, 4, 6, 8, 10 5: 5, 10, 15, 20 × × 3. 4: 4, 8, 12, 16 12: 12, 24, 36, 48 × × 4. 8: 8, 16, 24, 32 6: 6, 12, 18, 24 × ×

5 th Grade Number Sense 2.3 (5Q) Solve simple problems, including ones arising in concrete situations, involving the addition and subtraction of fractions and mixed numbers (like and unlike denominators of 20 or less), and express answers in the simplest form. Lesson to be used by EDI-trained teachers only. DataWORKS Educational Research (800) ©2012 All rights reserved. Comments? Subtract fractions with unlike denominators. Step #1: Read the problem and identify fractions, if necessary. (circle) Step #2: Find the least common denominator. Hint: Find the lowest shared multiple. Step #3: Create equivalent fractions. Hint: Use the least common denominator. Step #4: Subtract fractions. Hint: Subtract the numerators, keep the denominators the same. a. Reduce the difference, if possible. Step #5: Interpret the difference. CFU (#2) How did I/you find the least common denominator? (#3) How did I/you create equivalent fractions? (#4) How did I/you subtract fractions? To subtract fractions, both fractions must have like denominators. Skill Development/Guided Practice (continued) 5. Sherry bought of a pound of red apples and of a pound of green apples. How much more red apples than green apples does Sherry have? Sherry has ____ of a pound more red apples than green apples. 4: 4, 8, 12, 16 2: 2, 4, 6, 8 6. Tom bought of a pound of oranges and of a pound of bananas. How much more oranges than bananas did he buy? Tom bought ____ of a pound more oranges than bananas. ×× 3: 3, 6, 9, 12, 15 5: 5, 10, 15, 20 ××

5 th Grade Number Sense 2.3 (5Q) Solve simple problems, including ones arising in concrete situations, involving the addition and subtraction of fractions and mixed numbers (like and unlike denominators of 20 or less), and express answers in the simplest form. Lesson to be used by EDI-trained teachers only. DataWORKS Educational Research (800) ©2012 All rights reserved. Comments? There is of the pie left. Relevance 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? 1. Subtracting fractions will help solve real-life problems. To subtract fractions, both fractions must have like denominators. Sample Test Question 53. A B C D 2. Subtracting fractions will help you do well on tests. of the pie was left over after the party. Erick just ate of the pie. How much pie is left?  

5 th Grade Number Sense 2.3 (5Q) Solve simple problems, including ones arising in concrete situations, involving the addition and subtraction of fractions and mixed numbers (like and unlike denominators of 20 or less), and express answers in the simplest form. Lesson to be used by EDI-trained teachers only. DataWORKS Educational Research (800) ©2012 All rights reserved. Comments? Skill Closure To subtract fractions, both fractions must have like denominators. Subtract fractions with unlike denominators. Step #1: Read the problem and identify fractions, if necessary. (circle) Step #2: Find the least common denominator. Hint: Find the lowest shared multiple. Step #3: Create equivalent fractions. Hint: Use the least common denominator. Step #4: Subtract fractions. Hint: Subtract the numerators, keep the denominators the same. a. Reduce the difference, if possible. Step #5: Interpret the difference Carmen bought of a pound of grapes and of a pound of nectarines. How many more pounds of nectarines than grapes did Carmen buy? Carmen bought ____ of a pound more grapes than nectarines. Constructed Response Closure Which pair of fractions is ready to be subtracted? Explain your answer. A B __________________________________________________ Summary Closure What did you learn today about subtracting fractions with unlike denominators? Day 1 ______________________________________________________________ Day 2 ______________________________________________________________ 4: 4, 8, 12, 16 8: 8, 16, 24, 32 ×× 4: 4, 8, 12, 16 2: 2, 4, 6, 8 × ×

5 th Grade Number Sense 2.3 (5Q) Solve simple problems, including ones arising in concrete situations, involving the addition and subtraction of fractions and mixed numbers (like and unlike denominators of 20 or less), and express answers in the simplest form. Lesson to be used by EDI-trained teachers only. DataWORKS Educational Research (800) ©2012 All rights reserved. Comments? Subtract fractions with unlike denominators. Step #1: Read the problem and identify fractions, if necessary. (circle) Step #2: Find the least common denominator. Hint: Find the lowest shared multiple. Step #3: Create equivalent fractions. Hint: Use the least common denominator. Step #4: Subtract fractions. Hint: Subtract the numerators, keep the denominators the same. a. Reduce the difference, if possible. Step #5: Interpret the difference. To subtract fractions, both fractions must have like denominators. Independent Practice Name __________________________ 6: 6, 12, 18, : 3, 6, 9, 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? Jason ate ____ of a pizza more than Jamie. × × 8: 8, 16, 24, 32 12: 12, 24, 36, 48 × × 7: 7, 14, 21, 28, 35 4: 4, 8, 12, 16, 20, 24, 28 ××

5 th Grade Number Sense 2.3 (5Q) Solve simple problems, including ones arising in concrete situations, involving the addition and subtraction of fractions and mixed numbers (like and unlike denominators of 20 or less), and express answers in the simplest form. Lesson to be used by EDI-trained teachers only. DataWORKS Educational Research (800) ©2012 All rights reserved. Comments? Subtract fractions with unlike denominators. Step #1: Read the problem and identify fractions, if necessary. (circle) Step #2: Find the least common denominator. Hint: Find the lowest shared multiple. Step #3: Create equivalent fractions. Hint: Use the least common denominator. Step #4: Subtract fractions. Hint: Subtract the numerators, keep the denominators the same. a. Reduce the difference, if possible. Step #5: Interpret the difference. To subtract fractions, both fractions must have like denominators. Periodic Review 1 Name __________________________ 12: 12, 24, : 4, 8, 12, 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? Geoff has ____ of a pound more cashews than pecans. × × 6: 6, 12, 18, 24, 32 12: 12, 24, 36, 48 × × 4: 4, 8, 12, 16 6: 6, 12, 18 ××

5 th Grade Number Sense 2.3 (5Q) Solve simple problems, including ones arising in concrete situations, involving the addition and subtraction of fractions and mixed numbers (like and unlike denominators of 20 or less), and express answers in the simplest form. Lesson to be used by EDI-trained teachers only. DataWORKS Educational Research (800) ©2012 All rights reserved. Comments? Subtract fractions with unlike denominators. Step #1: Read the problem and identify fractions, if necessary. (circle) Step #2: Find the least common denominator. Hint: Find the lowest shared multiple. Step #3: Create equivalent fractions. Hint: Use the least common denominator. Step #4: Subtract fractions. Hint: Subtract the numerators, keep the denominators the same. a. Reduce the difference, if possible. Step #5: Interpret the difference. To subtract fractions, both fractions must have like denominators. Periodic Review 2 Name __________________________ 6: 6, 12, 18, : 8, 16, Alfredo bought some fruit. He got of a pound of apples and of a pound of pears. How many more pounds of apples than pears did Alfredo buy? Alfredo bought ____ of a pound more apples than pears. × × 10: 10, 20, 30, 40 4: 4, 8, 12, 16, 20 × × 8: 8, 16, 24 4: 4, 8, 12 ××

5 th Grade Number Sense 2.3 (5Q) Solve simple problems, including ones arising in concrete situations, involving the addition and subtraction of fractions and mixed numbers (like and unlike denominators of 20 or less), and express answers in the simplest form. Lesson to be used by EDI-trained teachers only. DataWORKS Educational Research (800) ©2012 All rights reserved. Comments? Subtract fractions with unlike denominators. Step #1: Read the problem and identify fractions, if necessary. (circle) Step #2: Find the least common denominator. Hint: Find the lowest shared multiple. Step #3: Create equivalent fractions. Hint: Use the least common denominator. Step #4: Subtract fractions. Hint: Subtract the numerators, keep the denominators the same. a. Reduce the difference, if possible. Step #5: Interpret the difference. To subtract fractions, both fractions must have like denominators. Periodic Review 3 Name __________________________ 12: 12, 24, : 4, 8, 12, Alice bought some beans. She got of a pound of lima beans and of a pound of pinto beans. How many more pounds of pinto beans than lima beans did she buy? Alice bought ____ of a pound more pinto beans than lima beans. × × 5: 5, 10, 15, 20 10: 10, 20, 30 × × 8: 8, 16, 24, 32, 40 5: 5, 10, 15, 20, 25, 30, 35, 40 ××