Question

16．口算

$\frac{5}{9}$×15=	$\frac{3}{5}$×2=	$\frac{1}{4}$×$\frac{4}{5}$=	$\frac{1}{9}$×$\frac{3}{7}$=	$\frac{7}{12}$×$\frac{3}{4}$=
$\frac{3}{4}$×$\frac{1}{5}$=	$\frac{6}{11}$×$\frac{1}{12}$=	$\frac{3}{22}$×$\frac{11}{13}$=	$\frac{7}{6}$×24=	$\frac{4}{7}$×$\frac{3}{8}$=

Answer 1

分析 根據(jù)分?jǐn)?shù)乘法的計算法則，依次進行解答即可．

解答 解：

$\frac{5}{9}$×15=$\frac{25}{3}$	$\frac{3}{5}$×2=$\frac{6}{5}$	$\frac{1}{4}$×$\frac{4}{5}$=$\frac{1}{5}$	$\frac{1}{9}$×$\frac{3}{7}$=$\frac{1}{21}$	$\frac{7}{12}$×$\frac{3}{4}$=$\frac{7}{16}$
$\frac{3}{4}$×$\frac{1}{5}$=$\frac{3}{20}$	$\frac{6}{11}$×$\frac{1}{12}$=$\frac{1}{22}$	$\frac{3}{22}$×$\frac{11}{13}$=$\frac{3}{26}$	$\frac{7}{6}$×24=28	$\frac{4}{7}$×$\frac{3}{8}$=$\frac{3}{14}$

點評 明確分?jǐn)?shù)乘法的計算法則，是解答此題的關(guān)鍵．