Add & Subtract Like Fractions
0011 0010 1010 1101 0001 0100 1011
7th Grade Math
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Lesson Objective:
Students will add and subtract
fractions with like denominators.
Vocabulary
0011 0010 1010 1101 0001 0100 1011
• Like Fractions
– Fractions with common denominators
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Adding Like Fractions
0011 0010 1010 1101 0001 0100 1011
• Add. Write in simplest form.
5 2
 
9 9
5 2

9
7
9
3  1
    
5  5
 3  ( 1)

5
4

5
1
2
4
Adding Like Fractions
0011 0010 1010 1101 0001 0100 1011
• Add. Write in simplest form.
3 1
  
7 7
 31

7
2

7
1  2
   
3  3
1  ( 2)

3
1

3
1
2
4
Whiteboard Practice
0011 0010 1010 1101 0001 0100 1011
• Add. Write in simplest form.
4 3
 
5 5
1  5
    
9  9
3  7
   
8  8
5 6
 
7 7
1
2
4
Subtracting Like Fractions
0011 0010 1010 1101 0001 0100 1011
• Subtract. Write in simplest form.
9 1
 
10 10
9 1

10
8 4
or
10 5
5 3
  
8 8
 5  3  5  ( 3)

8
8
8
 or  1
8
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2
4
Subtracting Like Fractions
0011 0010 1010 1101 0001 0100 1011
• Subtract. Write in simplest form.
5  2
   
9  9
5  ( 2) 5  2

9
9
7
9
11  5 
    
12  12 
 11  ( 5)  11  5

12
12
6
1
 or 
12
2
1
2
4
Whiteboard Practice
0011 0010 1010 1101 0001 0100 1011
• Subtract. Write in simplest form.
9 3
 
10 10
5  1
   
14  14 
5 2
  
9 9
1
2
4
15  7 
    
16  16 
Real World Example
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• About 6/100 of the population of the United
States lives in Florida. Another 4/100 loves
in Ohio. How much more of the U.S.
population lives in Florida than in Ohio?
6
4


100 100
64
2
1

or
100 100 50
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Whiteboard Practice
0011 0010 1010 1101 0001 0100 1011
• In Mr. Navarro’s first period class, 17/28 of
the students got an A on their math test. In
his second period class, 11/28 of the
students got an A. What fraction more of
the students got an A in Mr. Navarro’s first
period class than his second period class?
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Whiteboard Practice
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• Of the 50 states in the United States, 14
have an Atlantic Ocean coastline and 5 have
a Pacific Ocean coastline. What fraction of
U.S. states have either an Atlantic Ocean or
Pacfic Ocean coastline?
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