Adding and Subtracting Fractions

Unlike denominators

100

1/2 + 2/3 

7/6

200

1/3+3/2

11/6

300

3/4-1/3

5/12

400

1/5+2/6

16/30

500

3/8-2/9

11/72

Common denominators

100

1/2+1/2

2/2 or 1

200

6/8-2/8

4/8

300

10/12+11/12

21/12

400

21/25-18/25

3/25

500

35/50+12/50

47/50

Adding

100

3/4+2/12

11/12

200

4/8+8/16

16/16 or 1 

300

4/12+3/24

9/24

400

1/9+3/27

6/27

500

5/15+8/75

33/75

Subtracting

100

8/9-1/3

3/9

200

5/4-2/8

8/8 or 1

300

8/10-3/20

13/20

400

10/12- 24/36

6/36

500

8/11 - 60/99

12/99