5 th Grade Math Learning Objective: We will subtract fractions with unlike denominators. READY TO TEACH SM EDI ® Lessons ©2013 All rights reserved. EDI Lesson Overview Focus Standard:5.NF.1 Add and subtract fractions with unlike denominators (including mixed numbers) by replacing given fractions with equivalent fractions in such a way as to produce an equivalent sum or difference of fractions with like denominators. For example, 2/3 + 5/4 = 8/ /12 = 23/12. (In general, a/b + c/d = (ad + bc)/bd.) Support Standard:5.NF.2 Solve word problems involving addition and subtraction of fractions referring to the same whole, including cases of unlike denominators, e.g., by using visual fraction models or equations to represent the problem. Use benchmark fractions and number sense of fractions to estimate mentally and assess the reasonableness of answers. For example, recognize an incorrect result 2/5 + 1/2 = 3/7, by observing that 3/7 < 1/2. SMP 2, SMP 3, SMP 4, SMP 6 Prerequisite(s):4.NF.3.a Understand addition and subtraction of fractions as joining and separating parts referring to the same whole. Manipulative(s): Special Instructions: Vocabulary Academic:identify, interpret Content:least common denominator, equivalent, difference Support:

CCSS 5 th Grade Numbers and Operations – Fractions 1.2 Add and subtract fractions with unlike denominators (including mixed numbers) by replacing given fractions with equivalent fractions with like denominators. Lesson to be used by EDI-trained teachers only. READY TO TEACH SM EDI ® Lessons ©2013 All rights reserved. What are we going to do? CFU 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 The least common denominator (LCD) is the lowest multiple shared by a set of denominators. We will subtract fractions with unlike denominators. Learning Objective Activate Prior Knowledge 2: 2, 4, 6, 8 3: 3, 6, 9, 12 Find the least common denominator of the fractions below : 5, 10, 15, 20 2: 2, 4, 6, 8, 10 The LCD of and is 3. The LCD of and is numerator denominator Fraction

CCSS 5 th Grade Numbers and Operations – Fractions 1.2 Subtract fractions with unlike denominators. Lesson to be used by EDI-trained teachers only. ©2013 All rights reserved. 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 ________.” CFU Concept Development 2 3 numerator denominator Fraction Subtracting Fractions with Unlike Denominators   3 5 The LCD of and 1 2 is 10. Equivalent Fractions × 6 10 = × 5 =  Fractions with unlike denominators have a different number of equal parts. Fractions with like denominators have the same 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 fractions with like denominators

CCSS 5 th Grade Numbers and Operations – Fractions 1.2 Subtract fractions with unlike denominators. Lesson to be used by EDI-trained teachers only. ©2013 All rights reserved. 1 equal value 2 answer to a subtraction problem 3 explain Vocabulary Skill Development/Guided Practice Find the least common denominator. Hint: Find the lowest shared multiple. Create equivalent 1 fractions with like denominators. Hint: Use the least common denominator. Subtract fractions. Hint: Subtract the numerators, keep the denominators the same. Reduce the difference 2, if possible. Interpret 3 the difference. “___ minus ____ equals ____.” Subtract fractions with unlike denominators a To subtract fractions, both fractions must have like denominators. How did I/you find the least common denominator? How did I/you create equivalent fractions? How did I/you subtract fractions? CFU : 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 × ×

CCSS 5 th Grade Numbers and Operations – Fractions 1.2 Subtract fractions with unlike denominators. Lesson to be used by EDI-trained teachers only. ©2013 All rights reserved. Skill Development/Guided Practice (continued) 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 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 ×× Sherry bought ____ of a pound more ______________ than _______________. milk chocolate white chocolate Tom bought ____ of a pound more __________ than ___________. cauliflower celery 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 required = needed relevant = has to do with problem reasonableness = possible

CCSS 5 th Grade Numbers and Operations – Fractions 1.2 Subtract fractions with unlike denominators. Lesson to be used by EDI-trained teachers only. ©2013 All rights reserved. There is of the pie left. of the pie was left over after the party. Erick just ate of the pie. How much pie is left? += += 1 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? CFU 2 Relevance Subtracting fractions will help you do well on tests. To subtract fractions, both fractions must have like denominators. += Sample Test Question: 53. A B C D Subtracting fractions will help solve real-life problems.

CCSS 5 th Grade Numbers and Operations – Fractions 1.2 Subtract fractions with unlike denominators. Lesson to be used by EDI-trained teachers only. ©2013 All rights reserved. 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? What did you learn today about subtracting fractions with unlike denominators? (Pair-Share) Use words from the word bank. Access Common Core Summary Closure 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 ____.” Subtract fractions with unlike denominators a To subtract fractions, both fractions must have like denominators. Skill Closure Which pair of fractions is ready to be subtracted? Explain your answer. A B 1. 4: 4, 8, 12, 16 8: 8, 16, 24, 32 ×× 4: 4, 8, 12, 16 2: 2, 4, 6, 8 × × Carmen bought ____ of a pound more __________ than ___________. grapes nectarines Word Bank fractions like/unlike denominator least common denominator equivalent

CCSS 5 th Grade Numbers and Operations – Fractions 1.2 Subtract fractions with unlike denominators. Lesson to be used by EDI-trained teachers only. ©2013 All rights reserved. Independent Practice To subtract fractions, both fractions must have like denominators. 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? × × 8: 8, 16, 24, 32 12: 12, 24, 36, 48 × × 7: 7, 14, 21, 28, 35 4: 4, 8, 12, 16, 20, 24, 28 ×× _________ ate ____ of a pizza more than _________. Jamie Jason 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 ____.” Subtract fractions with unlike denominators a

CCSS 5 th Grade Numbers and Operations – Fractions 1.2 Subtract fractions with unlike denominators. Lesson to be used by EDI-trained teachers only. ©2013 All rights reserved. Periodic Review 1 Access Common Core 12: 12, 24, : 4, 8, 12, 16 × × 2. 6: 6, 12, 18, 24, 32 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? Geoff has ____ of a pound more ___________ than __________. 4: 4, 8, 12, 16 6: 6, 12, 18 ×× Abdul subtracted the fractions below. His teacher, Mrs. Treadwell, says that his answer is incorrect. Explain the mistake that Abdul made. pecans cashews

CCSS 5 th Grade Numbers and Operations – Fractions 1.2 Subtract fractions with unlike denominators. Lesson to be used by EDI-trained teachers only. ©2013 All rights reserved. Periodic Review 2 Access Common Core 6: 6, 12, 18, : 8, 16, × × 10: 10, 20, 30, 40 4: 4, 8, 12, 16, 20 × × Horatio added the fractions below. Some of his answers are incorrect. Circle all the incorrect answers and write the correct solutions.

CCSS 5 th Grade Numbers and Operations – Fractions 1.2 Subtract fractions with unlike denominators. Lesson to be used by EDI-trained teachers only. ©2013 All rights reserved. Periodic Review 3 Access Common Core 12: 12, 24, : 4, 8, 12, × × 5: 5, 10, 15, 20 10: 10, 20, 30 × × Choose Yes or No to show whether each choice is equal to the difference of. YesNo

CCSS 5 th Grade Numbers and Operations – Fractions 1.2 Subtract fractions with unlike denominators. Lesson to be used by EDI-trained teachers only. ©2013 All rights reserved. EDI – Cognitive, Teaching, and English Learner Strategies Learning Objective: We will subtract fractions with unlike denominators. Elaboration Targeted Vocabulary Academic identify, interpret Content least common denominator, equivalent, difference Support Demonstration Vocabulary Strategy Multiple-Meaning Synonym identify, interpret Definition least common denominator, equivalent, difference Homophone Internal Context Clue Listen, Speak Similar Sounds WriteWriting Read Tracked Reading Comprehensible Input Cognates Contextual Clues Graphic Organizer Contextualized Definitions Pictures Language Strategies Cognitive StrategiesTeaching Strategies Content Access Strategies