笔算乘法从个位乘起,笔算除法也是从个位除起. .
3:2==15÷ = %= (填小数)
4÷ ==12.5%=3: =.
0.625= ÷40=40: == %.
:5=0.8== ÷20= %.
2: =4÷ === %, .