Adding

1
Adding SubtractingFractions with Like and
Unlike Denominators
2
Check Skills
1
 
 
4
 
 


8
 
 
28
 
 


 
 
 
 


24
5
3
Parts of a Fraction
numerator the number of parts we are dealing
with
3
4
denominator the total number of parts that
equal a whole
4
Adding Like Denominators
Only add the numerators
1/4
1/4
4

4
1/4
1/4
1

5
Add these fractions
1/5
4
1/5


5
1/5
1/5
6
Subtract these fractions
1/4
1/4
1
-

4
1/4
7
Add these fractions
1
1
1
6
6
6
5

6
1
1
6
6
8
Subtract these fractions
1
1
1
6
6
6
3

6
1
1
6
6
9
Simplify Your Answer
3
3
1



6
3
2
1 x 3
1 x 6
2 x 3
10
Practice
8
3
5
4
2





12
12
12
4
3
1 x 12
1 x 8
2 x 6
2 x 4
3 x 4
11
Practice
3
3
6
3
1

-



9
9
9
3
3
1 x 9
1 x 3
3 x 3
12
Practice
5
3
8
5
1

-



15
15
15
5
3
1 x 15
1 x 5
3 x 5
13
Practice
12
3
9
4
3





20
20
20
4
5
1 x 20
1 x 12
2 x 10
2 x 6
4 x 5
3 x 4
14
We need a common denominator to add these
fractions.

15
Count by 2's
2, 4, 6, 8, 10, 12, 14, 16, 18, 20
Count by 7's
7, 14, 21, 28, 35
16
7
x 7
Re-write Fractions with the new denominator

X 7
Make equivalent fractions.
6
x 2


x 2
Add the numerators
13
7 6 13
17
We need a common denominator to add these
fractions.

Count by 7's
7, 14, 21, 28, 35, 42, 49, 56, 63
Count by 5's
5, 10, 15, 20, 25, 30, 35, 40, 45
18
15
x 5
Re-write Fractions with the new denominator

X 5
Make equivalent fractions.
7
x 7


x 7
Add the numerators
22
15 7 22
19
We need a common denominator to add these
fractions.
Count by 7's
7, 14, 21, 28, 35, 42, 49, 56, 63
Count by 8's
8, 16, 24, 32, 40, 48, 56, 64, 72
20
32
x 8
Re-write Fractions with the new denominator

x 8
Make equivalent fractions.
21
x 7


x 7
Add the numerators
53
32 21 53
21
We need a common denominator to add these
fractions.

Count by 3's
3, 6, 9, 12, 15, 18, 21, 24, 27
Count by 5's
5, 10, 15, 20, 25, 30, 35, 40, 45
22
Re-write Fractions with the new denominator
9
x 3

X 3
Make equivalent fractions.
x 5
10

Add the numerators

9 10 19
x 5
Change to Mixed
19
1

23
We need a common denominator to subtract a
fraction from another.
-
Count by 5's
5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55
Count by 11's
11, 22, 33, 44, 55, 66, 77
24
15
x 5
Re-write Fractions with the new denominator

x 5
11
x 11
Make equivalent fractions.

-
x 11
4
Subtract.
15 - 11 4
25
We need a common denominator to subtract one
fraction from another.
-
Count by 2's
2, 4, 6, 8, 10, 12, 14, 16, 18, 20
Count by 10's
10, 20, 30
26
5
x 5
Make equivalent fractions.

x 5
Subtract.
3
5 3 2
x 1
-
Simplify

x 1
2
2

2
27
Try These
A
D
E
B
F
C
28
Answers On Next Slide

• Each click on the next slide reveals an answer.
• Check your papers.
• If you discover an incorrect answer, be able to
  explain your mistake.

29
Try These
A
D
B
E
F
C