Question

15．計(jì)算下面各題．

$\frac{2}{13}$×3=	$\frac{1}{4}$×12=	18×$\frac{5}{16}$=	42×$\frac{9}{28}$=
$\frac{9}{44}$×22=	$\frac{18}{21}$×$\frac{7}{9}$=	$\frac{23}{24}$×$\frac{8}{69}$=	$\frac{5}{7}$×$\frac{4}{15}$=

Answer 1

分析 分?jǐn)?shù)乘法：分子相乘的積做分子，分母相乘的積做分母，能約分的先約分；由此進(jìn)行計(jì)算即可．

解答 解：

$\frac{2}{13}$×3=$\frac{6}{13}$	$\frac{1}{4}$×12=3	18×$\frac{5}{16}$=$\frac{45}{8}$	42×$\frac{9}{28}$=$\frac{27}{2}$
$\frac{9}{44}$×22=$\frac{9}{2}$	$\frac{18}{21}$×$\frac{7}{9}$=$\frac{2}{3}$	$\frac{23}{24}$×$\frac{8}{69}$=$\frac{1}{9}$	$\frac{5}{7}$×$\frac{4}{15}$=$\frac{4}{21}$

點(diǎn)評(píng) 本題考查了簡(jiǎn)單的分?jǐn)?shù)乘法計(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)．