12×=
×=
27÷=
×4.5=
÷=
3.5:1.4=
1÷-=
x
4
10
20
y
6
9
15
24
A
B
8
4.8
16÷20%= 4.8÷(0.4+1.2)=
-(-)= 12÷0.25÷4=