READY TO TEACH SM EDI ® Lessons ©2013 All rights reserved. EDI Lesson Overview Focus Standard:4.NF.3a Understand addition and subtraction of fractions.

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CCSS 4th Grade Numbers and Operations – Fractions 3.0a.2Understand addition and subtraction of fractions as joining and

separating parts referring to the same whole.Lesson to be used by EDI-trained teachers only.

READY TO TEACHSM EDI® Lessons©2013 All rights reserved.

What are we going to do?What are we going to do?

CFUCFU

Students, you already know how to reduce fractions to the lowest terms. Now, we will use reducing fractions when subtracting fractions with like denominators.

Students, you already know how to reduce fractions to the lowest terms. Now, we will use reducing fractions when subtracting fractions with like denominators.

Make ConnectionMake Connection

Learning ObjectiveLearning Objective

Activate Prior Knowledge

Activate Prior Knowledge

We will subtract fractions with like denominators.

1

Equivalent fractions are fractions that have the same value.

Find the equivalent fractions below.

1. 612÷

26

6

2. 412

3

44

1

23

numerator

denominator

Fraction

©2013 All rights reserved.

CCSS 4th Grade Numbers and Operations – Fractions 3.0a.2Subtract fractions with like denominators.

Lesson to be used by EDI-trained teachers only.

Concept DevelopmentConcept Development

Fractions with like denominators have the same number of equal parts.To subtract fractions, both fractions must have a like denominator.•The difference of fractions must be reduced to the lowest terms.

Subtracting Fractions

Adolfo has eight-twelfths of a pie. If he eats two-twelfths of the pie how much of the pie is left?

23

numerator

denominator

FractionAnimated

Which subtraction problem has fractions with like denominators? How do you know?

A

B

Which subtraction problem has fractions with like denominators? How do you know?

A

B

CFUCFU

612

212

412

46

8 26128

122

12




Which of the following is an example of a reduced fraction? How do you know?

A

B

In your own words what is reducing a fraction? Reducing a fraction is _______.

Which of the following is an example of a reduced fraction? How do you know?

A

B

In your own words what is reducing a fraction? Reducing a fraction is _______.

CFUCFU

Reducing Fractions

Concept Development (Clarification and CFU)

Concept Development (Clarification and CFU)

Equivalent fractions are fractions that have the same value.•Reducing a fraction is finding the equivalent fraction in the lowest terms.

“Not in the lowest terms.”“In the lowest terms.”

23

numerator

denominator

Fraction

126 2

2 63 3

3 21

38

48




Subtract the fractions. (write) Keep the same denominator.Subtract the numerators.

Reduce the difference, if needed.Read the difference out loud. “___ minus ___ equals ___.”

Subtract fractions with like denominators.1

23

a

b

Skill Development/Guided Practice

Skill Development/Guided Practice

How did I/you subtract the fractions?

How did I/you subtract the fractions?

CFUCFU

1

To subtract fractions, both fractions must have a like denominator.•The difference of fractions must be reduced to the lowest terms.

1. 2.

4.3.

23

numerator

denominator

Fraction

25

15

36

26

58

28

88

38

15

16

38

58







23

a

b

Skill Development/Guided Practice (continued)


How did I/you subtract the fractions?How did I/you reduce the difference?


CFUCFU

1

2

To subtract fractions, both fractions must have a like denominator.•The difference of fractions must be reduced to the lowest terms. 2

3numerator

denominator

Fraction

5.

7.

34

14

78

38

24

6.

8.

56

36

910

310

22

12

26

22

13

48

44

12

610

22

35







23

a

b





CFUCFU

1

2


3numerator

denominator

Fraction

9.

11.

1012

112

58

38

912

10.

12.

612

212

610

410

33

34

412

44

13

28

22

14

210

22

15






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?

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?

CFUCFU

2

1

3

4

5

Liu has a piece of ribbon that is of an inch long. She cuts the ribbon into two pieces. One piece is of an inch long. How long is the other piece of ribbon?

Angela has of a pie. Her family eats of the pie. How much of the pie is left?

910

410

510

55

12

The other piece of ribbon is an inch long.

58

38

28

22

14

Angela has of the pie left.




Subtracting fractions with like denominators will help you while cooking.

Subtracting fractions with like denominators will help you do well on tests.

1

Does anyone else have another reason why it is relevant to subtract fractions with like denominators? (Pair-Share) Why is it relevant to subtract fractions with like denominators? You may give one of my reasons or one of your own. Which reason is more relevant to you? Why?

Does anyone else have another reason why it is relevant to subtract fractions with like denominators? (Pair-Share) Why is it relevant to subtract fractions with like denominators? You may give one of my reasons or one of your own. Which reason is more relevant to you? Why?

CFUCFU

2

RelevanceRelevance

Abdul is baking a batch of muffins. He has ¾ of a cup of blueberries. The recipe calls for ¼ cup of blueberries. He will have ½ cup of blueberries left.

Sample Test Question:

42. Which of the following equations correctly subtracts the fractions?

Yes No

Yes No

Yes No

Yes No








23

a

b

Skill ClosureSkill Closure

Access Common CoreAccess Common Core

Summary ClosureSummary Closure

Abel has subtracted the fractions below. Mrs. Lee says that the answer is incorrect. Explain the mistake that Abel made.


23

numerator

denominator

Fraction

What did you learn today about subtracting fractions with like denominators? (Pair-Share)Use words from the word bank.

Word Bank

fractionnumerator

denominatorreduce

710

210

1. 810

110

710

2. 512

112

412

44

13

Abel’s math is correct, but he did not reduce his answer. The correct answer is .




Independent PracticeIndependent Practice

1.

3.

36

16

710

310

26

2. 78

58

22

13

28

22

14

410

22

4. 4

10 2

102

1022

15




23

a

b


3numerator

denominator

Fraction

25




Independent Practice (continued)

Independent Practice (continued)

5.

7.

612

312

58

18

312

6. 48

38

33

14

18

48

44

8. 8

12 4

124

1244

13




23

a

b


3numerator

denominator

Fraction

12




Periodic Review 1Periodic Review 1


Which of the following fractions are correctly subtracted and reduced?

1. 510

310

210

2. 48

28

22

15

28

22

14

Yes No

Yes No

Yes No

Yes No

612

312

312

1112

612

50

612

312

34

512

312

16






Bradley subtracted the fractions below. Some of his answers are incorrect. Circle all the incorrect answers and write the correct solutions.

1. 412

312

112

2. 512

512

012

= 0

38

38

210

110

36

16

24

14

512

412

610

210

36

36

510

310

34

14

910

410

38

18

68

18






1. 412

412

012

2. 512

112

= 0 412

44

13

Yes No

Yes No

Yes No36

Yes No60

Choose Yes or No to show whether each choice

represents the difference of .1012

412




EDI – Cognitive, Teaching, and English Learner Strategies

Learning Objective: We will subtract fractions with like denominators.

Elaboration

Targeted Vocabulary

Academic

Content fraction, numerator, denominator, reduce

Support

Demonstration

VocabularyStrategy

Multiple-Meaning

Synonym

Definition fraction, numerator, denominator, reduceHomophone

Internal Context Clue

Listen, Speak Similar Sounds

Write Writing

Read Tracked Reading

Comprehensible Input

Cognates

Contextual Clues

Graphic Organizer

Contextualized Definitions

Pictures

Language Strategies

Cognitive Strategies Teaching Strategies

Content Access Strategies

READY TO TEACH SM EDI ® Lessons ©2013 All rights reserved. EDI Lesson Overview Focus Standard:4.NF.3a Understand addition and subtraction of fractions.

Documents

equivalent fractions

subtraction of fractions

operations fractions

fractions adolfo

difference of fractions

concept development

like denominators

reduced fraction