分析:(1)把32看作8×4,運(yùn)用乘法結(jié)合律簡(jiǎn)算;
(2)先算括號(hào)內(nèi)的,再算除法;
(3)運(yùn)用乘法分配律簡(jiǎn)算;
(4)把9.9看作10-0.1,運(yùn)用乘法分配律簡(jiǎn)算;
(5)先算乘除,再算加法;
(6)先算括號(hào)內(nèi)的,再算括號(hào)外的除法,最后算加法.
解答:解:(1)12.5×32×2.5
=12.5×8×4×2.5
=(12.5×8)×(4×2.5)
=100×10
=1000;
(2)(1-0.2)÷(1-0.84)
=0.8÷0.16
=5;
(3)9.16×2.5-0.5×9.16
=9.16×(2.5-0.5)
=9.16×2
=18.32;
(4)6.8×9.9
=6.8×(10-0.1)
=6.8×10-0.68
=68-0.68
=67.32;
(5)0.22×1.5+1.541÷2.3
=0.33+0.67
=1;
(6)(5.15-3.25)×0.4+0.36
=1.9×0.4+0.36
=0.76+0.36
=1.12.
點(diǎn)評(píng):此題考查了小數(shù)的四則混合運(yùn)算,注意運(yùn)算順序和運(yùn)算法則,靈活運(yùn)用所學(xué)的運(yùn)算定律簡(jiǎn)便計(jì)算.