Question

1．快速計(jì)算．

$\frac{2}{3}$×9	$\frac{1}{5}$×4                $\frac{3}{4}$×8	$\frac{5}{7}$×5                  $\frac{3}{16}$×8
$\frac{3}{5}$×0	$\frac{5}{18}$×20             $\frac{2}{3}$×20	5×$\frac{9}{10}$                  $\frac{5}{24}$×8

Answer 1

分析 根據(jù)分?jǐn)?shù)乘整數(shù)的計(jì)算方法求解：分子與整數(shù)相乘的積做分子，分母不變，能約分的先約分再計(jì)算．

解答 解：

$\frac{2}{3}$×9=6	$\frac{1}{5}$×4=$\frac{4}{5}$                $\frac{3}{4}$×8=6	$\frac{5}{7}$×5=$\frac{25}{7}$                 $\frac{3}{16}$×8=$\frac{3}{2}$
$\frac{3}{5}$×0=0	$\frac{5}{18}$×20=$\frac{50}{9}$             $\frac{2}{3}$×20=$\frac{40}{3}$	5×$\frac{9}{10}$=$\frac{9}{2}$                 $\frac{5}{24}$×8=$\frac{5}{3}$

點(diǎn)評(píng) 本題考查了分?jǐn)?shù)乘整數(shù)的計(jì)算，計(jì)算時(shí)要細(xì)心，注意把結(jié)果化成最簡(jiǎn)分?jǐn)?shù)，能約分的先約分可以使計(jì)算簡(jiǎn)化．