3.簡(jiǎn)算
0.25×3.2×12.5
12.5×9.7-8.7×12.5
93.6÷8÷1.25.
分析 ①把3.2寫成4×0.8,根據(jù)乘法結(jié)合律計(jì)算;
②根據(jù)乘法分配律進(jìn)行計(jì)算;
③根據(jù)減法性質(zhì)進(jìn)行計(jì)算.
解答 解:①0.25×3.2×12.5
=0.25×4×0.8×12.5
=(0.25×4)×(0.8×12.5)
=1×10
=10
②12.5×9.7-8.7×12.5
=12.5×(9.7-8.7)
=12.5×1
=12.5
③93.6÷8÷1.25
=93.6÷(8×1.25)
=93.6÷10
=9.36
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.