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 根據(jù)分數(shù)小數(shù)加減乘除法的計算方法解答．

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

點評 口算時，注意數(shù)據(jù)特點和運算符號，細心解答即可．