Question

2．甲、乙兩數(shù)的比是4：5，甲數(shù)比乙數(shù)少$\frac{1}{5}$，乙數(shù)比甲數(shù)多$\frac{1}{4}$．

Answer 1

分析 根據(jù)“甲乙兩數(shù)的比是4：5”可得，把甲數(shù)看作4份，那么乙數(shù)就是5份，求甲數(shù)比乙數(shù)少幾分之幾，就是求甲數(shù)比乙數(shù)少的數(shù)是乙數(shù)的幾分之幾，根據(jù)求一個數(shù)是另一個數(shù)的幾分之幾用除法計算，所以用甲數(shù)比乙數(shù)少的數(shù)（5-4）除以乙數(shù)．，同樣用乙數(shù)比甲數(shù)多的數(shù)除以甲數(shù)就是乙數(shù)比甲數(shù)多幾分之幾．

解答 解：（5-4）÷5
=1÷5
=$\frac{1}{5}$；
（5-4）÷4
=1÷4
=$\frac{1}{4}$；
答：甲數(shù)比乙數(shù)少$\frac{1}{5}$，乙數(shù)比甲數(shù)多$\frac{1}{4}$．
故答案為：$\frac{1}{5}，\frac{1}{4}$．

點評 本題關(guān)鍵是把兩個數(shù)的比轉(zhuǎn)化為各自的份數(shù)，然后根據(jù)“求一個數(shù)是另一個數(shù)的幾分之幾是多少，用除法計算”解答．