把9本书放进两个抽屉里,至少有 本书要放在同一个抽屉中.
=20÷ =0.4=4: = %
= ÷ = (最后结果填小数).
4﹕ ﹦﹦﹦20÷ ﹦ %
÷ ===0.75.
= :24= %= (填小数)