分析:(1)25×27×4,運(yùn)用乘法交換律和結(jié)合律進(jìn)行簡(jiǎn)算;
(2)(125+3)×8,運(yùn)用乘法分配律進(jìn)行簡(jiǎn)算;
(3)102×25,轉(zhuǎn)化為(100+2)×25,再運(yùn)用乘法分配律進(jìn)行簡(jiǎn)算;
(4)375×14+25×14,運(yùn)用乘法分配律進(jìn)行簡(jiǎn)算;
(5)42+99×42,運(yùn)用乘法分配律進(jìn)行簡(jiǎn)算;
(6)38×99,轉(zhuǎn)化為38×(100-1),運(yùn)用乘法分配律進(jìn)行簡(jiǎn)算.
解答:解:(1)25×27×4,
=27×(25×4),
=27×100,
=2700;
(2)(125+3)×8,
=125×8+3×8,
=1000+24,
=1024;
(3)102×25,
=(100+2)×25,
=100×25+2×25,
=2500+50,
=2550;
(4)375×14+25×14,
=(375+25)×14,
=400×14,
=5600;
(5)42+99×42,
=42×(99+1),
=42×100,
=4200;
(6)38×99,
=38×(100-1),
=38×100-38×1,
=3800-38,
=3762.
點(diǎn)評(píng):此題考查的目的是理解掌握乘法交換律、結(jié)合律、分配律的意義,并且能夠運(yùn)用這些運(yùn)算定律進(jìn)行簡(jiǎn)便計(jì)算.