Question

19．直接寫出得數(shù)

14×$\frac{9}{28}$	$\frac{23}{24}$×$\frac{8}{69}$	$\frac{21}{65}$×$\frac{26}{35}$	$\frac{9}{44}$×33
$\frac{9}{10}$×$\frac{2}{3}$×$\frac{5}{6}$	$\frac{5}{4}$×$\frac{1}{8}$×16	$\frac{2}{9}$×34×18×$\frac{3}{17}$

Answer 1

分析 根據(jù)分?jǐn)?shù)乘法的計(jì)算方法解答，$\frac{9}{10}$×$\frac{2}{3}$×$\frac{5}{6}$根據(jù)乘法交換律和結(jié)合律進(jìn)行簡算，$\frac{5}{4}$×$\frac{1}{8}$×16根據(jù)乘法結(jié)合律進(jìn)行簡算，$\frac{2}{9}$×34×18×$\frac{3}{17}$根據(jù)乘法交換律和結(jié)合律進(jìn)行簡算．

解答 解：

14×$\frac{9}{28}$=$\frac{9}{2}$	$\frac{23}{24}$×$\frac{8}{69}$=$\frac{1}{9}$	$\frac{21}{65}$×$\frac{26}{35}$=$\frac{6}{25}$	$\frac{9}{44}$×33=$\frac{27}{4}$
$\frac{9}{10}$×$\frac{2}{3}$×$\frac{5}{6}$=$\frac{1}{2}$	$\frac{5}{4}$×$\frac{1}{8}$×16=$\frac{5}{2}$	$\frac{2}{9}$×34×18×$\frac{3}{17}$=24

點(diǎn)評(píng) 直接寫得數(shù)時(shí)，注意數(shù)據(jù)特點(diǎn)和運(yùn)算符號(hào)，能用運(yùn)算定律進(jìn)行簡算的要簡算．