Question

15．白面民小六年級(jí)同學(xué)參加植樹(shù)活動(dòng)，原計(jì)劃植樹(shù)320棵，實(shí)際比計(jì)劃多植80棵，實(shí)際植樹(shù)的棵數(shù)是原計(jì)劃的幾分之幾？實(shí)際比原計(jì)劃多植百分之幾？

Answer 1

分析 把計(jì)劃植樹(shù)的棵數(shù)看成單位“1”，先用計(jì)劃植樹(shù)的棵數(shù)加上多植的棵數(shù)，求出實(shí)際植樹(shù)的棵數(shù)，用實(shí)際植樹(shù)的棵數(shù)除以計(jì)劃植樹(shù)的棵數(shù)，即可求出實(shí)際植樹(shù)的棵數(shù)是原計(jì)劃的幾分之幾；再用多植的棵數(shù)除以計(jì)劃植樹(shù)的棵數(shù)，即可求出實(shí)際比原計(jì)劃多植百分之幾．

解答 解：（320+80）÷320
=400÷320
=$\frac{5}{4}$
80÷320=25%
答：實(shí)際植樹(shù)的棵數(shù)是原計(jì)劃的$\frac{5}{4}$，實(shí)際比原計(jì)劃多植25%．

點(diǎn)評(píng) 本題是求一個(gè)數(shù)是另一個(gè)數(shù)的百分之幾（幾分之幾），關(guān)鍵是看把誰(shuí)當(dāng)成了單位“1”，單位“1”的量為除數(shù)．