Question

9．根據(jù)“楊樹(shù)棵數(shù)是柳樹(shù)棵數(shù)的$\frac{4}{5}$”這一信息可以知道②．

①楊樹(shù)棵數(shù)×$\frac{4}{5}$=柳樹(shù)棵數(shù)  ②柳樹(shù)棵數(shù)×$\frac{4}{5}$=楊樹(shù)棵數(shù) ③柳樹(shù)棵數(shù)÷楊樹(shù)棵數(shù)=$\frac{4}{5}$．

Answer 1

分析 首先根據(jù)題意，把柳樹(shù)棵數(shù)看作單位“1”，然后根據(jù)分?jǐn)?shù)乘法的意義，用柳樹(shù)棵數(shù)乘$\frac{4}{5}$，即可得到楊樹(shù)棵數(shù)；然后判斷出：楊樹(shù)棵數(shù)÷柳樹(shù)棵數(shù)=$\frac{4}{5}$．

解答 解：因?yàn)椤皸顦?shù)棵數(shù)是柳樹(shù)棵數(shù)的$\frac{4}{5}$”，
所以柳樹(shù)棵數(shù)×$\frac{4}{5}$=楊樹(shù)棵數(shù)，楊樹(shù)棵數(shù)÷柳樹(shù)棵數(shù)=$\frac{4}{5}$．
故選：②．

點(diǎn)評(píng) 此題主要考查了分?jǐn)?shù)乘法的意義的應(yīng)用，要熟練掌握，解答此題的關(guān)鍵是要明確：求一個(gè)數(shù)的幾分之幾是多少，用乘法解答．