簡便計(jì)算.
(1)37+128+53+72+10
(2)25×8×125×4
(3)25×64
(4)(125×6)×72
(5)125×88
(6)7×125×25×32.
解:(1)37+128+53+72+10,
=(128+72)+(37+53+10),
=200+100,
=300;
(2)25×8×125×4,
=(25×4)×(8×125),
=100×1000,
=100000;
(3)25×64,
=25×4×16,
=100×16,
=1600;
(4)(125×6)×72,
=125×8×6×9,
=1000×54,
=54000;
(5)125×88,
=125×80+125×8,
=10000+1000,
=11000;
(6)7×125×25×32,
=7×(125×8)×(25×4),
=7×1000×100,
=700000.
分析:(1)運(yùn)用加法交換律和結(jié)合律解答;
(2)運(yùn)用乘法交換律和結(jié)合律解答;
(3)化64=4×16,再運(yùn)用乘法結(jié)合律解答;
(4)化72=8×9,再運(yùn)用乘法結(jié)合律解答;
(5)運(yùn)用乘法分配律解答;
(6)化32=8×4,再運(yùn)用乘法交換律和結(jié)合律解答.
點(diǎn)評:本題主要考查學(xué)生正確運(yùn)用簡便方法解決問題的能力.