簡(jiǎn)便計(jì)算.
(1)101×59
(2)35+35×73+26×35
(3)6×127+71×2×3+12
(4)21×96+84
(5)25×(8+4)×125
(6)25×(8×4)×125.
解:(1)101×59,
=100×59+1×59,
=5900+59,
=5959;
(2)35+35×73+26×35,
=35×(1+73+26),
=35×100,
=3500;
(3)6×127+71×2×3+12,
=6×127+71×6+6×2,
=6×(127+71+2),
=6×200,
=1200;
(4)21×96+84,
=21×96+21×4,
=21×(96+4),
=21×100,
=2100;
(5)25×(8+4)×125,
=(25×8+25×4)×125,
=(200+100)×125,
=300×125,
=37500;
(6)25×(8×4)×125,
=(25×4)×(8×125),
=100×1000,
=100000.
分析:(1)101×59,轉(zhuǎn)化為:(100+1)×59,運(yùn)用乘法分配律簡(jiǎn)算;
(2)35+35×73+26×35,運(yùn)用乘法分配律簡(jiǎn)算;
(3)6×127+71×2×3+12,轉(zhuǎn)化為:6×127+71×6+6×2,運(yùn)用乘法分配律簡(jiǎn)算;
(4)21×96+84,轉(zhuǎn)化為:21×96+21×4,運(yùn)用乘法分配律簡(jiǎn)算;
(5)25×(8+4)×125運(yùn)用乘法分配律簡(jiǎn)算;
(6)25×(8×4)×125,運(yùn)用乘法交換律和結(jié)合律簡(jiǎn)算.
點(diǎn)評(píng):此題考查的目的是理解掌握乘法的運(yùn)算定律,并且能夠靈活運(yùn)用乘法的運(yùn)算定律進(jìn)行簡(jiǎn)便計(jì)算.