Adding/Subtracting Fractions

Same denominator

100

1/4 + 1/4

2/4

200

3/8 + 2/8

5/8

300

4/12 + 6/12

10/12

400

8/16 - 3/16

5/16

500

9/10 - 5/10

4/10

Different denominator

100

1/2 + 1/4

1/2 (2/4) + 1/4 = 3/4

200

1/6 + 1/12

1/6 (2/12) + 1/12 =

3/12 = 1/4

300

1/3 + 1/5

1/3 (5/15) + 1/5 (3/15) = 

8/15

400

2/5 - 3/8

 2/5 (16/40) - 3/8 (15/40)

= 1/40

500

6/7 - 3/4

6/7 (24/28) - 3/4 (21/28)

= 3/28