用简便方法计算下面各题.(0.86+0.86+0.86+0.86)×25 4÷1+6×125÷(50÷8) 7.6×÷[1.9﹣1.9×(1.9﹣1.9)].
在横线里填上合适的数:===,== 9÷ ====.
0.7÷5=7: == %.
=0.375=21÷ =6: = %.
5:6可以写成5÷6,比值是1.2.所以2:3:4=2÷3÷4. .
3÷8═= ÷24= %= :56.