25X40=1000

12.4-3.6=8.8

12.5X8=100

1／2+1／3=5／6

2.75+3.65=6.4

4.2÷0.2=21

910÷70=13

1.2X0.8=0.96

15X300=4500

7.2÷0.09=80

9-0.9=0.1

10÷0.1=100

1／5÷2／3=3／10

9.9÷3=3.3

0.06X0.3=0.018