根據(jù)題中的已知條件和所求的問(wèn)題,將補(bǔ)充的條件和對(duì)應(yīng)的算式連起來(lái):
果園里有蘋(píng)果樹(shù)80棵,,梨樹(shù)有多少棵?
蘋(píng)果樹(shù)比梨樹(shù)多60% 80÷60%
梨樹(shù)是蘋(píng)果樹(shù)的60% 80×(1+60%)
梨樹(shù)比蘋(píng)果樹(shù)少60% 80×60%
蘋(píng)果樹(shù)是梨樹(shù)的60% 80×(1-60%)
梨樹(shù)比蘋(píng)果樹(shù)多60% 80÷(1+60%)
蘋(píng)果樹(shù)比梨樹(shù)少60% 80÷(1-60%)
解:
分析:蘋(píng)果樹(shù)比梨樹(shù)多60%,把梨樹(shù)的棵數(shù)看作單位“1”,單位“1”不知道用除法進(jìn)行解答,列式為:80÷(1+60%)
梨樹(shù)是蘋(píng)果樹(shù)的60%,把蘋(píng)果的棵數(shù)看作單位“1”單位“1”知道用乘法進(jìn)行計(jì)算,列式為:80×60%
梨樹(shù)比蘋(píng)果樹(shù)少60%,把蘋(píng)果的棵數(shù)看作單位“1”單位“1”知道用乘法進(jìn)行計(jì)算,列式為:80×(1-60%)
蘋(píng)果樹(shù)是梨樹(shù)的60%,把梨樹(shù)的棵數(shù)看作單位“1”,單位“1”不知道用除法進(jìn)行解答,列式為:80÷60%
梨樹(shù)比蘋(píng)果樹(shù)多60%,把蘋(píng)果的棵數(shù)看作單位“1”單位“1”知道用乘法進(jìn)行計(jì)算,列式為80×(1+60%).
蘋(píng)果樹(shù)比梨樹(shù)少60%,把梨樹(shù)的棵數(shù)看作單位“1”,單位“1”不知道用除法進(jìn)行解答,列式為:80÷(1-60%)
點(diǎn)評(píng):此題主要考查百分?jǐn)?shù)乘除應(yīng)用題的一般形式:由兩個(gè)數(shù)量以及兩個(gè)數(shù)量之間的倍比關(guān)系構(gòu)成;這道題是已知一個(gè)數(shù)量和兩個(gè)數(shù)量之間的關(guān)系,求另一個(gè)數(shù)量,用乘法解答,單位“1”已知;用除法解答,單位“1”未知.