括号里最大能填几?30× <220 40× <140 60× <20024× <250 35× <235 36× <280.
÷3==15: .
24÷ = :30== %=0.4.
÷12=12:15= %= 小数.
=12: =× = ÷5=2.
÷ =20: ==0.8= %.