1.25×0.25×0.05×64???????????
20.06×65+380×2.006-2.006×30.
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解:1.25×0.25×0.05×64,
=1.25×0.25×0.05×(8×4×2),
=(1.25×8)×(0.25×4)×(0.05×2),
=10×1×0.1,
=1;
20.06×65+380×2.006-2.006×30,
=20.06×65+(380-30)×2.006,
=20.06×65+350×2.006,
=20.06×65+(350÷10)×(2.006×10),
=20.06×65+35×20.06,
=20.06×(65+35),
=20.06×100,
=2006.
解析分析:1.25×0.25×0.05×64,先把64分成8×4×2,然后利用乘法的结合律进行简算;??????????20.06×65+380×2.006-2.006×30,后边的乘减乘算式里有共同的因数2.006,先利用乘法分配律,再根据积不变规律,最后根据乘法分配律进行简算.
点评:此题考查了乘法结合律及乘法分配律的灵活运用.