Show:
adding fractions
100

1/5 + 4/5=

1 

200

3/10 + 9/10 =

1 1/5 

300

12/50 + 49/50=

1 8/25 

400

12/15 + 12/5 = 

3 1/5 

500

5000/10,000 + 7000/ 20,000

43/50