Question

17．直接寫得數(shù)．

$\frac{1}{3}$×1=	$\frac{1}{4}$×$\frac{2}{5}$=	$\frac{5}{6}$×18=	$\frac{7}{12}$×$\frac{3}{14}$=	15×$\frac{3}{5}$=
0.18×$\frac{7}{18}$=	$\frac{2}{3}$×$\frac{9}{10}$=	$\frac{4}{25}$×100=	1.2×$\frac{1}{6}$=	$\frac{4}{11}$×$\frac{11}{4}$=

Answer 1

分析 分數(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．

解答 解：

$\frac{1}{3}$×1=$\frac{1}{3}$	$\frac{1}{4}$×$\frac{2}{5}$=$\frac{1}{10}$	$\frac{5}{6}$×18=15	$\frac{7}{12}$×$\frac{3}{14}$=$\frac{1}{8}$	15×$\frac{3}{5}$=9
0.18×$\frac{7}{18}$=0.07	$\frac{2}{3}$×$\frac{9}{10}$=$\frac{3}{5}$	$\frac{4}{25}$×100=16	1.2×$\frac{1}{6}$=0.2	$\frac{4}{11}$×$\frac{11}{4}$=1

點評 本題考查了分數(shù)乘法的計算方法，要注意先約分，再計算更簡便．