Question

14．脫式計(jì)算，能簡(jiǎn)便就簡(jiǎn)便．
$\frac{3}{5}$$÷6÷\frac{1}{15}$
$\frac{9}{5}$×$\frac{2}{3}$$÷\frac{18}{35}$
$\frac{4}{7}$$÷\frac{6}{5}$×$\frac{7}{15}$
$\frac{27}{4}$×$\frac{10}{9}$×$\frac{27}{5}$．

Answer 1

分析 （1）（2）把除法變?yōu)槌朔ǎs分計(jì)算；
（3）運(yùn)用乘法結(jié)合律簡(jiǎn)算．

解答 解：（1）$\frac{3}{5}$÷6÷$\frac{1}{15}$
=$\frac{3}{5}$×$\frac{1}{6}$×15
=$\frac{3}{2}$

（2）$\frac{9}{5}$×$\frac{2}{3}$$÷\frac{18}{35}$
=$\frac{9}{5}$×$\frac{2}{3}$×$\frac{35}{18}$
=$\frac{7}{3}$

（3）$\frac{4}{7}$$÷\frac{6}{5}$×$\frac{7}{15}$
=$\frac{4}{7}$×$\frac{5}{6}$×$\frac{7}{15}$
=$\frac{2}{9}$

（4）$\frac{27}{4}$×$\frac{10}{9}$×$\frac{27}{5}$
=$\frac{27}{4}$×（$\frac{10}{9}$×$\frac{27}{5}$）
=$\frac{27}{4}$×6
=$\frac{81}{2}$

點(diǎn)評(píng) 本題考查了學(xué)生通過約分對(duì)分?jǐn)?shù)四則混合運(yùn)題目進(jìn)行簡(jiǎn)算的能力．