分析:(1)102×0.35,運(yùn)用乘法分配律進(jìn)行簡(jiǎn)算;
(2)(8+0.8)×1.25,運(yùn)用乘法分配律進(jìn)行簡(jiǎn)算;
(3)7.7×1.7+2.3×7.7,運(yùn)用乘法分配律進(jìn)行簡(jiǎn)算,
(4)2.98×0.25×40,運(yùn)用乘法結(jié)合律進(jìn)行簡(jiǎn)算;
(5)0.28×99,轉(zhuǎn)化為:0.28×(100-1),再運(yùn)用乘法分配律進(jìn)行簡(jiǎn)算;
(6)0.44×2.5,轉(zhuǎn)化為:0.11×4×2.5,再運(yùn)用乘法結(jié)合律進(jìn)行簡(jiǎn)算.
解答:解:(1)102×0.35,
=100×0.35+2×0.35,
=35+0.7,
=35.7;
(2)(8+0.8)×1.25,
=8×1.25+0.8×1.25,
=100+10,
=110;
(3)7.7×1.7+2.3×7.7,
=7.7×(1.7+2.3),
=7.7×4,
=30.8;
(4)2.98×0.25×40,
=2.98×(0.25×40),
=2.98×10,
=29.8;
(5)0.28×99,
=0.28×(100-1),
=0.28×100-0.28×1,
=28-0.28,
=27.72;
(6)0.44×2.5,
=0.11×4×2.5,
=0.11×(4×2.5),
=0.11×10,
=1.1.
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,并且能夠靈活運(yùn)用這些運(yùn)算定律進(jìn)行簡(jiǎn)便計(jì)算.