Question

8．計(jì)算（寫出過程）．

42×$\frac{9}{28}$	$\frac{9}{44}$×11	$\frac{23}{24}$×$\frac{8}{69}$	$\frac{15}{16}$×$\frac{20}{21}$×$\frac{1}{5}$
$\frac{9}{10}$×$\frac{2}{3}$×$\frac{5}{6}$	$\frac{5}{4}$×$\frac{1}{8}$×16	5÷$\frac{15}{14}$	$\frac{5}{6}$÷$\frac{1}{18}$
$\frac{7}{10}$÷$\frac{5}{6}$	$\frac{4}{5}$÷28×$\frac{7}{5}$	$\frac{22}{7}$÷16×$\frac{14}{33}$	（$\frac{7}{8}$-$\frac{5}{6}$）÷$\frac{11}{24}$

Answer 1

分析 根據(jù)分?jǐn)?shù)乘除法的計(jì)算方法進(jìn)行解答即可．

解答 解：（1）42×$\frac{9}{28}$
=$\frac{42×9}{28}$
=$\frac{27}{2}$；

（2）$\frac{9}{44}$×11
=$\frac{9×11}{44}$
=$\frac{9}{4}$；

（3）$\frac{23}{24}$×$\frac{8}{69}$
=$\frac{23×8}{24×69}$
=$\frac{1}{9}$；

（4）$\frac{15}{16}$×$\frac{20}{21}$×$\frac{1}{5}$
=$\frac{15×20×1}{16×21×5}$
=$\frac{5}{28}$；

（5）$\frac{9}{10}$×$\frac{2}{3}$×$\frac{5}{6}$
=$\frac{9×2×5}{10×3×6}$
=$\frac{1}{2}$；

（6）$\frac{5}{4}$×$\frac{1}{8}$×16
=$\frac{5×1×16}{4×8}$
=$\frac{5}{2}$；

（7）5÷$\frac{15}{14}$
=5×$\frac{14}{15}$
=$\frac{5×14}{15}$
=$\frac{14}{3}$；

（8）$\frac{5}{6}$÷$\frac{1}{18}$
=$\frac{5}{6}$×18
=$\frac{5×18}{6}$
=15；

（9）$\frac{7}{10}$÷$\frac{5}{6}$
=$\frac{7}{10}$×$\frac{6}{5}$
=$\frac{7×6}{10×5}$
=$\frac{14}{25}$；

（10）$\frac{4}{5}$÷28×$\frac{7}{5}$
=$\frac{4}{5}$×$\frac{1}{28}$×$\frac{7}{5}$
=$\frac{4×1×7}{5×28×5}$
=$\frac{1}{25}$；

（11）$\frac{22}{7}$÷16×$\frac{14}{33}$
=$\frac{22}{7}$×$\frac{1}{16}$×$\frac{14}{33}$
=$\frac{22×1×14}{7×16×33}$
=$\frac{1}{12}$；

（12）（$\frac{7}{8}$-$\frac{5}{6}$）÷$\frac{11}{24}$
=（$\frac{7}{8}$-$\frac{5}{6}$）×$\frac{24}{11}$
=$\frac{7}{8}$×$\frac{24}{11}$-$\frac{5}{6}$×$\frac{24}{11}$
=$\frac{21}{11}$-$\frac{20}{11}$
=$\frac{1}{11}$．

點(diǎn)評(píng) 此題考查了分?jǐn)?shù)四則運(yùn)算，注意運(yùn)算順序，靈活運(yùn)用運(yùn)算定律進(jìn)行簡(jiǎn)算即可．