Adding Fractions with Unlike Denominators
Subtracting Fractions with Unlike Denominators
Least Common Denominator
100

1/4 + 2/3 = 

11/12

100

4/5 - 1/3 =

7/15

100

1/2 and 3/5

LCD: 10

200

4/9 + 1/6 =

*write your answer in simplest form 

11/18

200

4/3 - 2/7 =

22/21 

200

5/12 and 2/9

LCD: 36

300

3/4 + 1/9 =

31/36

300

3/4 - 1/9 =

23/36

300

1/7 and 4/8

LCD: 56

400

1/2 + 1/3 =

5/6

400

6/7 - 1/2 =

5/14

400

9/10 and 5/6

LCD: 30

500

1/4 + 3/7 =

19/28

500

9/10 - 1/4 =

*Write your answer in simplest form 

13/20

500

1/4 and 2/3

LCD: 12