口算下面各题
8 ÷2 = 9 ÷3=
60 ÷3 = 80 ÷2=
20
40
6÷3 = 90 ÷3=
30
50 X 2= 800÷4=
100
200
20 X 4= 800 X 3 =
80
2400
