①287×25×4
②35×98
③168×327+168×673
④125×64
⑤125×15×4
⑥(1500-250-25)×2.
解:①287×25×4,
=287×(25×4),
=287×100,
=28700;
②35×98,
=35×(100-2),
=35×100-35×2,
=3500-70,
=3430;
③168×327+168×673,
=168×(327+673),
=168×1000,
=168000;
④125×64,
=125×(8×8),
=125×8×8,
=1000×8,
=8000;
⑤125×15×4,
=125×4×15,
=500×15,
=7500;
⑥(1500-250-25)×2,
=1500×2-250×2-25×2,
=3000-500-50,
=2500-50,
=2450.
分析:①運用乘法結(jié)合律簡算;
②先把98分解成100-2,再運用乘法分配律簡算;
③運用乘法分配律簡算;
④先把64分解成8×8,再運用乘法結(jié)合律簡算;
⑤運用乘法交換律簡算;
⑥運用乘法分配律簡算.
點評:完成本題要注意分析式中數(shù)據(jù),運用合適的簡便方法計算.