Question

10．直接写出得数．

$\begin{array}{l}\frac{1}{2}\end{array}$×$\begin{array}{l}\frac{2}{3}\end{array}$=	$\begin{array}{l}\frac{5}{4}\end{array}$×8=	$\begin{array}{l}\frac{15}{16}\end{array}$÷5=	$\begin{array}{l}\frac{9}{20}\end{array}$÷$\begin{array}{l}\frac{3}{5}\end{array}$=
$\begin{array}{l}\frac{19}{32}\end{array}$×$\begin{array}{l}\frac{16}{19}\end{array}$=	$\begin{array}{l}\frac{2}{5}\end{array}$÷$\begin{array}{l}\frac{1}{10}\end{array}$=	（$\begin{array}{l}\frac{2}{3}\end{array}$π）÷（$\begin{array}{l}\frac{2}{3}\end{array}$π）=	$\begin{array}{l}\frac{7}{10}\end{array}$÷$\begin{array}{l}\frac{7}{5}\end{array}$×0=

Answer 1

分析 根据分数四则运算的计算法则及混合运算的运算顺序进行口算即可．

解答 解：

$\begin{array}{l}\frac{1}{2}\end{array}$×$\begin{array}{l}\frac{2}{3}\end{array}$=$\frac{1}{3}$	$\begin{array}{l}\frac{5}{4}\end{array}$×8=10	$\begin{array}{l}\frac{15}{16}\end{array}$÷5=$\frac{3}{16}$	$\begin{array}{l}\frac{9}{20}\end{array}$÷$\begin{array}{l}\frac{3}{5}\end{array}$=$\frac{3}{4}$
$\begin{array}{l}\frac{19}{32}\end{array}$×$\begin{array}{l}\frac{16}{19}\end{array}$=$\frac{1}{2}$	$\begin{array}{l}\frac{2}{5}\end{array}$÷$\begin{array}{l}\frac{1}{10}\end{array}$=4	（$\begin{array}{l}\frac{2}{3}\end{array}$π）÷（$\begin{array}{l}\frac{2}{3}\end{array}$π）=1	$\begin{array}{l}\frac{7}{10}\end{array}$÷$\begin{array}{l}\frac{7}{5}\end{array}$×0=0

点评 此题考查了分数四则运算的计算法则的运用．