Question

7．直接写出得数．

$\frac{3}{4}$-$\frac{1}{4}$=	$\frac{2}{3}$÷3=	$\frac{11}{12}$-$\frac{1}{12}$=	$\frac{4}{5}$÷8=
$\frac{3}{5}$×2=	$\frac{8}{9}$÷12=	$\frac{5}{12}$×4=	$\frac{7}{12}$÷7=
$\frac{1}{9}$×0=	$\frac{2}{5}$×4=	$\frac{11}{12}$×6=	$\frac{3}{20}$×$\frac{4}{5}$=
2÷$\frac{2}{5}$=	$\frac{5}{6}$×$\frac{3}{10}$=	2÷$\frac{2}{7}$=	$\frac{3}{4}$×$\frac{1}{5}$÷$\frac{3}{4}$×$\frac{1}{5}$=

Answer 1

分析 根据分数加减乘除法的计算方法进行计算．
$\frac{3}{4}$×$\frac{1}{5}$÷$\frac{3}{4}$×$\frac{1}{5}$根据乘法交换律和结合律进行简算．

解答 解：

$\frac{3}{4}$-$\frac{1}{4}$=$\frac{1}{2}$	$\frac{2}{3}$÷3=$\frac{2}{9}$	$\frac{11}{12}$-$\frac{1}{12}$=$\frac{5}{6}$	$\frac{4}{5}$÷8=$\frac{1}{10}$
$\frac{3}{5}$×2=$\frac{6}{5}$	$\frac{8}{9}$÷12=$\frac{2}{27}$	$\frac{5}{12}$×4=$\frac{5}{3}$	$\frac{7}{12}$÷7=$\frac{1}{12}$
$\frac{1}{9}$×0=0	$\frac{2}{5}$×4=$\frac{8}{5}$	$\frac{11}{12}$×6=$\frac{11}{2}$	$\frac{3}{20}$×$\frac{4}{5}$=$\frac{3}{25}$
2÷$\frac{2}{5}$=5	$\frac{5}{6}$×$\frac{3}{10}$=$\frac{1}{4}$	2÷$\frac{2}{7}$=7	$\frac{3}{4}$×$\frac{1}{5}$÷$\frac{3}{4}$×$\frac{1}{5}$=$\frac{1}{25}$

点评 口算时，注意运算符号和数据，然后再进一步计算．