Question

9．遞等式計(jì)算．
287+15170÷74×308-8569
[（1.4+$\frac{1}{3}$）÷1.04]×3.6
$\frac{1}{0.04}$-[1-（1-0.5×$\frac{1}{3}$）]
$\frac{2}{5}$×10.1+0.4×$\frac{3}{5}$+（$\frac{7}{10}$-0.3）×0.3-40%

Answer 1

分析 ①算式中有加減乘除，先計(jì)算乘除再計(jì)算加減．
②先計(jì)算括號(hào)里面的，再計(jì)算括號(hào)外面的乘法；
③先計(jì)算括號(hào)里面的，再計(jì)算括號(hào)外面的減法；
④運(yùn)用乘法的分配律進(jìn)行計(jì)算即可．

解答 解：①287+15170÷74×308-8569
=287+205×308-8569
=287+63140-8569
=54858

②[（1.4+$\frac{1}{3}$）÷1.04]×3.6
=[（$\frac{7}{5}$$+\frac{1}{3}$）×$\frac{25}{26}$]×3.6
=[$\frac{26}{15}$×$\frac{25}{26}$]×3.6
=$\frac{5}{3}$×3.6
=6


③$\frac{1}{0.04}$-[1-（1-0.5×$\frac{1}{3}$）]
=25-[1-（1-$\frac{1}{6}$）]
=25-$\frac{1}{6}$
=24$\frac{5}{6}$

④$\frac{2}{5}$×10.1+0.4×$\frac{3}{5}$+（$\frac{7}{10}$-0.3）×0.3-40%
=0.4×10.1+0.4×0.5+0.4×0.3-0.4
=0.4×（10.1+0.5+0.3-1）
=0.4×10
=4

點(diǎn)評(píng) 考查了運(yùn)算定律與簡(jiǎn)便運(yùn)算，四則混合運(yùn)算．注意運(yùn)算順序和運(yùn)算法則，靈活運(yùn)用所學(xué)的運(yùn)算律簡(jiǎn)便計(jì)算．