简算:0.25×4.78×40.65×2011.2×2.5+0.8×2.54.8×0.256.53÷0.4÷2.51.8×20.1.

发布时间:2020-07-31 11:02:12

简算:0.25×4.78×40.65×2011.2×2.5+0.8×2.54.8×0.256.53÷0.4÷2.51.8×20.1.

网友回答

解:(1)0.25×4.78×4,
=(0.25×4)×4.78,
=1×4.78,
=4.78;

(2)0.65×201,
=0.65×(200+1),
=0.65×100+0.65×1,
=130+0.65,
=130.65;

(3)1.2×2.5+0.8×2.5,
=(1.2+0.8)×2.5,
=2×2.5,
=5;

(4)4.8×0.25,
=1.2×4×0.25,
=1.2×(4×0.25),
=1.2×1,
=1.2;

(5)6.53÷0.4÷2.5,
=6.53÷(0.4×2.5),
=6.53÷1,
=6.53;

(6)1.8×20.1,
=1.8×(20+0.1),
=1.8×20+1.8×0.1,
=36+0.18,
=36.18.
解析分析:(1)运用乘法的交换律、结合律进行简算;(2)把201化成200+1,再运用乘法的分配律进行简算;(3)运用乘法的分配律进行简算;(4)把4.8化成1.2×4,再运用乘法的分配律进行简算;(5)运用乘法的运算定律进行简算;(6)把20.1化成20+0.1,再运用乘法的分配律进行简算.

点评:此题考查了小数四则混合运算的顺序,灵活运用运算定律进行简算.
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