Question

3．口算

$\frac{2}{5}$×6=	$\frac{2}{13}$÷$\frac{2}{5}$=	20÷$\frac{4}{5}$=	$\frac{1}{2}$+$\frac{1}{5}$=	2$\frac{1}{3}$×$\frac{7}{4}$=
$\frac{1}{7}$×$\frac{2}{3}$=	5.6÷0.08=	$\frac{7}{9}$×$\frac{5}{8}$×0=	39×$\frac{7}{13}$×$\frac{2}{3}$=	30÷$\frac{5}{6}$=

Answer 1

分析 根据分数小数加减乘除法的计算方法解答．

解答 解：

$\frac{2}{5}$×6=$\frac{12}{5}$	$\frac{2}{13}$÷$\frac{2}{5}$=$\frac{5}{13}$	20÷$\frac{4}{5}$=25	$\frac{1}{2}$+$\frac{1}{5}$=$\frac{7}{10}$	2$\frac{1}{3}$×$\frac{7}{4}$=$\frac{49}{12}$
$\frac{1}{7}$×$\frac{2}{3}$=$\frac{2}{21}$	5.6÷0.08=70	$\frac{7}{9}$×$\frac{5}{8}$×0=0	39×$\frac{7}{13}$×$\frac{2}{3}$=14	30÷$\frac{5}{6}$=36

点评 口算时，注意数据特点和运算符号，细心解答即可．