分析:(1)運(yùn)用乘法結(jié)合律簡(jiǎn)算;
(2)運(yùn)用乘法分配律簡(jiǎn)算;
(3)把32看作8×4,運(yùn)用乘法結(jié)合律簡(jiǎn)算;
(4)運(yùn)用減法的性質(zhì)簡(jiǎn)算;
(5)運(yùn)用除法的性質(zhì)簡(jiǎn)算;
(6)運(yùn)用乘法分配律簡(jiǎn)算.
解答:解:(1)18.4×2.5×4,
=18.4×(2.5×4),
=18.4×10,
=184;
(2)11.98×99+11.98,
=11.98×(99+1),
=11.98×100,
=1198;
(3)1.25×32×0.25,
=1.25×8×4×0.25,
=(1.25×8)×(4×0.25),
=10×1,
=10;
(4)89.7-7.83-2.17,
=89.7-(7.83+2.17),
=89.7-10,
=79.7;
(5)50.2÷25÷0.4,
=50.2÷(25×0.4),
=50.2÷10,
=5.02;
(6)0.8×(12.5+25),
=0.8×12.5+25×4×0.2,
=10+20,
=30.
點(diǎn)評(píng):完成本題要注意分析式中數(shù)據(jù),運(yùn)用合適的簡(jiǎn)便方法計(jì)算.