Question

3．脫式計算

$\frac{4}{9}$÷$\frac{5}{6}$×$\frac{5}{8}$=	$\frac{12}{13}$×$\frac{1}{4}$÷$\frac{9}{16}$=	9×$\frac{7}{81}$÷$\frac{17}{30}$=
$\frac{11}{16}$×$\frac{8}{15}$÷$\frac{33}{2}$=	$\frac{3}{4}$÷12×$\frac{6}{5}$=	$\frac{1}{5}$÷$\frac{7}{25}$×$\frac{5}{7}$=

Answer 1

分析 這六道題都先把除法變?yōu)槌朔�，然后約分計算，得出答案．

解答 解：（1）$\frac{4}{9}$÷$\frac{5}{6}$×$\frac{5}{8}$
=$\frac{4}{9}$×$\frac{6}{5}$×$\frac{5}{8}$
=$\frac{1}{3}$

（2）$\frac{12}{13}$×$\frac{1}{4}$÷$\frac{9}{16}$
=$\frac{12}{13}$×$\frac{1}{4}$×$\frac{16}{9}$
=$\frac{16}{39}$

（3）9×$\frac{7}{81}$÷$\frac{17}{30}$
=$\frac{7}{9}$×$\frac{30}{17}$
=$\frac{70}{51}$

（4）$\frac{11}{16}$×$\frac{8}{15}$÷$\frac{33}{2}$
=$\frac{11}{30}$×$\frac{2}{33}$
=$\frac{1}{45}$

（5）$\frac{3}{4}$÷12×$\frac{6}{5}$
=$\frac{3}{4}$×$\frac{1}{12}$×$\frac{6}{5}$
=$\frac{3}{40}$

（6）$\frac{1}{5}$÷$\frac{7}{25}$×$\frac{5}{7}$
=$\frac{1}{5}$×$\frac{25}{7}$×$\frac{5}{7}$
=$\frac{25}{49}$

點評 本題考查了學(xué)生通過約分對分數(shù)四則混合運題目進行簡算的能力．