Subtract 1Subtract 3 Subtract same number Subtract numbers from their doubles Subtract 2.
5 th Grade Math Learning Objective: We will subtract fractions with unlike denominators. READY TO...
-
Upload
derrick-augustine-flowers -
Category
Documents
-
view
214 -
download
0
Transcript of 5 th Grade Math Learning Objective: We will subtract fractions with unlike denominators. READY TO...
CCSS 5th Grade Numbers and Operations – Fractions 1.2Add 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 TEACHSM 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
1 1,
2 3
3: 3, 6, 9, 12
Find the least common denominator of the fractions below.
1. 2.
5: 5, 10, 15, 20 2: 2, 4, 6, 8, 10
3 1,
5 2
The LCD of and is 3.1
2
1
3The LCD of and is 10.
3
51
2
23
numerator
denominator
Fraction
CCSS 5th Grade Numbers and Operations – Fractions 1.2Subtract 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
23
numerator
denominator
Fraction
Subtracting Fractions with Unlike Denominators
610
510
110
- =35
12
- =
35
The LCD of and12
is 10.
Equivalent Fractions
22
35
× 610
=55
12
× 510
=
- =
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.
23
25
23
13
CCSS 5th Grade Numbers and Operations – Fractions 1.2Subtract fractions with unlike denominators.
Lesson to be used by EDI-trained teachers only. ©2013 All rights reserved.
1 equal value2 answer to a subtraction problem3 explain
Vocabulary
Skill Development/Guided Practice
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 ____.”
Subtract fractions with unlike denominators.1234
5a
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
3
4
2: 2, 4, 6, 8
1 1
2 3 1.
3: 3, 6, 9, 121
2
1
3
6
6
3
3×
×
3
6
2
2
2
6
3 2
6 6
1
6
1
6
1 2
2 5 2.
2: 2, 4, 6, 8, 10 5: 5, 10, 15, 20
1
2
2
5
10
10
5
5×
×
5
10
2
2
4
10
5 4
10 10 1
10
1
10
3 1
4 12 3.
4: 4, 8, 12, 16 12: 12, 24, 36, 48
3
4
1
12
12
12
3
3×
×
9
12
1
1
1
12
9 1
12 12
8
12
2
3
2
3
4 1
8 6 4.
8: 8, 16, 24, 32 6: 6, 12, 18, 24
4
8
1
6
24
24
3
3×
×
12
24
4
4
4
24
12 4
24 24
8
24
1
3
1
3
CCSS 5th Grade Numbers and Operations – Fractions 1.2Subtract 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?
3
4
1
2
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?
2
3
1
5
3
4
1
24
4
1
1× ×
3
4
2
2
2
4
3 2
4 4
1
4
3: 3, 6, 9, 12, 15 5: 5, 10, 15, 20
2
3
1
515
15
5
5× ×
10
15
3
3
3
15
10 3
15 15
7
15
1
4Sherry bought ____ of a pound more ______________ than _______________.milk chocolate white chocolate
7
15Tom 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
2
1
3
4
5
required = needed relevant = has to do with problemreasonableness = possible
CCSS 5th Grade Numbers and Operations – Fractions 1.2Subtract fractions with unlike denominators.
Lesson to be used by EDI-trained teachers only. ©2013 All rights reserved.
There is of the pie left.
12
12
14
14
of the pie was left over after the party. Erick just ate of the pie. How much pie is left?
+ =
14
14+ =
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.
12
12 + =
Sample Test Question:
53.
A
B
C
D
1 1
3 4
1
51
101
121
11
Subtracting fractions will help solve real-life problems.
CCSS 5th Grade Numbers and Operations – Fractions 1.2Subtract 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.123
4
5a
To subtract fractions, both fractions must have like denominators.
Skill Closure
Which pair of fractions is ready to be subtracted? Explain your answer.
3 15 6
A 3 14 4
B
3 1
4 8 1. 4: 4, 8, 12, 16
8: 8, 16, 24, 32
3
4
1
88
8
2
2× ×
6
8
1
1
1
8
6 1
8 8
5
8
5
8
3
41
2
4: 4, 8, 12, 16 2: 2, 4, 6, 8
3
4
1
24
4
1
1× ×
3
4
2
2
2
4
3 2
4 4
1
41
4Carmen bought ____ of a pound more __________ than ___________.grapes nectarines
Word Bank
fractionslike/unlike
denominatorleast common denominatorequivalent
CCSS 5th Grade Numbers and Operations – Fractions 1.2Subtract 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, 24
5 2
6 3 1.
3: 3, 6, 9, 12
3 3
8 12 2.
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?
5
6
2
3
6
6
1
1×
×
5
6
2
2
4
6
5 4
6 6
1
6
1
6
8: 8, 16, 24, 32 12: 12, 24, 36, 48
3
8
3
12
24
24
3
3×
×
9
24
2
2
6
24
9 6
24 24
3
24
1
8
1
8
2
71
4
7: 7, 14, 21, 28, 35 4: 4, 8, 12, 16, 20, 24, 28
2
7
1
428
28
4
4× ×
8
28
7
7
7
28
8 7
28 28
1
28
1
28_________ ate ____ of a pizza more than _________.JamieJason
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.123
4
5a
CCSS 5th Grade Numbers and Operations – Fractions 1.2Subtract 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, 36
11 1
12 4 1.
4: 4, 8, 12, 1611
12
1
4
12
12
1
1×
×
11
12
3
3
3
12
11 3
12 12
8
12
2
3
2
3
3 4
6 12 2.
6: 6, 12, 18, 24, 32 12: 12, 24, 36, 48
3
6
4
12
12
12
2
2×
×
6
12
1
1
4
12
6 4
12 12
2
12
1
6
1
6
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 __________.
3
41
6
4: 4, 8, 12, 16 6: 6, 12, 18
3
4
1
612
12
3
3× ×
9
12
2
2
2
12
9 2
12 12
7
12
7
12
Abdul subtracted the fractions below. His teacher, Mrs. Treadwell, says that his answer is incorrect. Explain the mistake that Abdul made.
10 1
12 4
pecanscashews
CCSS 5th Grade Numbers and Operations – Fractions 1.2Subtract 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, 24
4 3
6 8 1.
8: 8, 16, 24
9 1
10 4 2.
4
6
3
8
24
24
4
4×
×
16
24
3
3
9
24
16 9
24 24
7
24
7
24
10: 10, 20, 30, 40 4: 4, 8, 12, 16, 20
9
10
1
4
20
20
2
2×
×
18
20
5
5
5
20
18 5
20 20
13
20
13
20
Horatio added the fractions below. Some of his answers are incorrect. Circle all the incorrect answers and write the correct solutions.
CCSS 5th Grade Numbers and Operations – Fractions 1.2Subtract 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, 36
11 3
12 4 1.
4: 4, 8, 12, 16
3 3
5 10 2.
11
12
3
4
12
12
1
1×
×
11
12
3
3
9
12
11 9
12 12
2
12
1
6
1
6
5: 5, 10, 15, 2010: 10, 20, 30
3
5
3
10
10
10
2
2×
×
6
10
1
1
3
10
6 3
10 10
3
10
3
10
Choose Yes or No to show whether each choice is
equal to the difference of .
Yes No
Yes No
Yes No
Yes No
CCSS 5th Grade Numbers and Operations – Fractions 1.2Subtract 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
VocabularyStrategy
Multiple-Meaning
Synonym identify, interpretDefinition least common denominator, equivalent, difference
Homophone
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