分析:(1)運用乘法的交換律、結(jié)合律進(jìn)行簡算,
(2)運用減法的性質(zhì)進(jìn)行簡算,
(3)先去括號,再運用加法的交換律、結(jié)合律進(jìn)行簡算,
(4)運用除法的性質(zhì)進(jìn)行簡算,
(5)運用乘法的分配律進(jìn)行簡算,
(6)把48化成6×8,再運用乘法的結(jié)合律進(jìn)行簡算.
解答:解:(1)25×29×4,
=(25×4)×29,
=100×29,
=2900;
(2)720-238-162,
=720-(238+162),
=720-400,
=320;
(3)612+(465+388),
=612+465+388,
=(612+388)+465,
=1000+465,
=1465;
(4)6000÷125÷8,
=6000÷(125×8),
=6000÷1000,
=6;
(5)169×28+131×28,
=(169+131)×28,
=300×28,
=8400;
(6)48×125,
=6×8×125,
=6×(8×125),
=6×1000,
=6000.
點評:此題考查了運算定律與簡便運算,四則混合運算.注意運算順序和運算法則,靈活運用所學(xué)的運算定律進(jìn)行簡便計算.