2.5÷=
4×3.14=
43-4.5=
628÷3.14=
4:0.25=
6÷1.5=
0.42:()3=
( ):9=
12÷0.9≈
12÷0.03=
25×40%=
2.4-2.4×0.5=
8×5÷8×5=
0.71 1.5小时90分