Question

13．靈活計(jì)算．
（7.25×40%+2$\frac{3}{4}$×$\frac{2}{5}$）÷20%              
3.5÷4+360×25%+0.25×36.5．

Answer 1

分析 （1）小括號里面根據(jù)乘法分配律進(jìn)行計(jì)算，最后算除法；
（2）根據(jù)乘法分配律進(jìn)行簡算．

解答 解：（1）（7.25×40%+2$\frac{3}{4}$×$\frac{2}{5}$）÷20%
=（7.25×0.4+2.75×0.4）÷20%
=（7.25+2.75）×0.4÷20%
=10×0.4÷20%
=4÷20%
=20；

（2）3.5÷4+360×25%+0.25×36.5
=3.5×0.25+360×0.25+0.25×36.5
=（3.5+360+36.5）×0.25
=400×0.25
=100．

點(diǎn)評 考查了運(yùn)算定律與簡便運(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)算定律進(jìn)行簡便計(jì)算．