Question

9．下面各題怎樣計(jì)算簡(jiǎn)便就怎樣算．
①0.125×56×8；
②（$\frac{1}{15}$+$\frac{2}{17}$）×15×17；
③3.5×$\frac{4}{5}$+5.5×80%+0.8．

Answer 1

分析 ①利用乘法交換律與結(jié)合律計(jì)算；
②、③利用乘法分配律計(jì)算．

解答 解：①0.125×56×8
=（0.125×8）×56
=1×56
=56

②（$\frac{1}{15}$+$\frac{2}{17}$）×15×17
=$\frac{1}{15}$×15×17+$\frac{2}{17}$×15×17
=17+30
=47

③3.5×$\frac{4}{5}$+5.5×80%+0.8
=0.8×（3.5+5.5+1）
=0.8×10
=8

點(diǎn)評(píng) 考查學(xué)生對(duì)四則運(yùn)算法則以及運(yùn)算定律的掌握情況．