解:(1)125×25×32,
=125×25×(8×4),
=(125×8)×(25×4),
=1000×100,
=100000;
(2)2300-165-35,
=2300-(165+35),
=2300-200,
=2100;
(3)25×204,
=25×(200+4),
=25×200+25×4,
=5000+100,
=5100;
(4)125×(8+4),
=125×8+125×4,
=1000+500,
=1500;
(5)3200÷25÷4,
=3200÷(25×4),
=3200÷100,
=32;
(6)56×32-46×32,
=(56-46)×32,
=10×32,
=320;
(7)432÷54+17×54,
=8+918,
=926;
(8)99×78+78,
=(99+1)×78,
=100×78,
=7800.
分析:(1)先把32分解成8×4,再運(yùn)用乘法結(jié)合律簡算;
(2)根據(jù)減法的性質(zhì)簡算;
(3)先把204分解成200+4,再運(yùn)用乘法分配律簡算;
(4)(6)(8)運(yùn)用乘法分配律簡算;
(5)根據(jù)除法的性質(zhì)簡算;
(7)先同時運(yùn)算除法和乘法,最后算加法.
點(diǎn)評:此題是考查四則混合運(yùn)算,要仔細(xì)觀察算式的特點(diǎn),靈活運(yùn)用一些定律進(jìn)行簡便計(jì)算.