甲數(shù)與乙數(shù)的比是5:7,甲數(shù)比乙數(shù)少________,乙數(shù)比甲數(shù)多________.
分析:甲數(shù)與乙數(shù)的比是5:7,那么甲數(shù)占5份,乙數(shù)占7份,(1)要求甲數(shù)比乙數(shù)少幾分之幾,是把乙數(shù)看作單位“1”,用甲乙兩數(shù)的差除以乙數(shù);
(2)要求乙數(shù)比甲數(shù)多幾分之幾,就是把甲數(shù)看作單位“1”,用甲乙兩數(shù)的差除以甲數(shù);據(jù)此解答.
解答:(1)(7-5)÷7,
=2÷7,
=
;
答:甲數(shù)比乙數(shù)少
.
(2)(7-5)÷5,
=2÷5,
=
;
答:乙數(shù)比甲數(shù)多
.
故答案為;
,
.
點評:本題考查了求一個數(shù)比另一個數(shù)多或少幾分之幾,就用多的或少的數(shù)除以單位“1”的數(shù),關(guān)鍵是看把誰當成了單位“1”,單位“1”的量就為除數(shù).