Question

15．口算．

$\frac{4}{5}$×3.5=	$\frac{4}{9}$×$\frac{3}{4}$=	5×$\frac{7}{10}$=	$\frac{6}{7}$×0=
$\frac{8}{17}$×0×$\frac{5}{8}$=	$\frac{1}{4}$×$\frac{2}{5}$=	$\frac{1}{4}$+$\frac{3}{4}$×$\frac{1}{3}$=	$\frac{5}{12}$×$\frac{12}{5}$=
12.1×$\frac{7}{11}$=	$\frac{5}{24}$×$\frac{8}{15}$=	$\frac{2}{3}$×18=	$\frac{3}{4}$×$\frac{1}{2}$=

Answer 1

分析 本題根據(jù)分數(shù)加法、減法、乘法、除法的運算法則計算即可．

解答 解：

$\frac{4}{5}$×3.5=2.8	$\frac{4}{9}$×$\frac{3}{4}$=$\frac{1}{3}$	5×$\frac{7}{10}$=$\frac{7}{2}$	$\frac{6}{7}$×0=0
$\frac{8}{17}$×0×$\frac{5}{8}$=0	$\frac{1}{4}$×$\frac{2}{5}$=$\frac{1}{10}$	$\frac{1}{4}$+$\frac{3}{4}$×$\frac{1}{3}$=$\frac{1}{2}$	$\frac{5}{12}$×$\frac{12}{5}$=1
12.1×$\frac{7}{11}$=7.7	$\frac{5}{24}$×$\frac{8}{15}$=$\frac{1}{9}$	$\frac{2}{3}$×18=12	$\frac{3}{4}$×$\frac{1}{2}$=$\frac{3}{8}$

點評 完成此類題目要根據(jù)運算法則認真分析式中數(shù)據(jù)，然后快速準確得出答案．