题目内容
用简便方法计算.
(1)47×0.125×8
(2)0.65×201
(3)0.02×48.8×50
(4)1.45×6.5+0.55×6.5
(5)0.625×0.8×0.04×0.5
(6)18.8×101-18.8.
(1)47×0.125×8
(2)0.65×201
(3)0.02×48.8×50
(4)1.45×6.5+0.55×6.5
(5)0.625×0.8×0.04×0.5
(6)18.8×101-18.8.
分析:(1)可根据乘法结合律计算;
(2)可先将201拆分为200+1后根据乘法分配律计算;
(3)可根据乘法交换律计算;
(4)(6)可根据乘法分配律计算;
(5)可根据乘法结合律计算;
(2)可先将201拆分为200+1后根据乘法分配律计算;
(3)可根据乘法交换律计算;
(4)(6)可根据乘法分配律计算;
(5)可根据乘法结合律计算;
解答:解:(1)47×0.125×8
=47×(0.125×8),
=47×1,
=47;
(2)0.65×201
=0.65×(200+1),
=0.65×200+0.65,
=130+0.65,
=130.65;
(3)0.02×48.8×50
=0.02×50×48.8,
=1×48.8,
=48.8;
(4)1.45×6.5+0.55×6.5
=(1.45+0.55)×6.5,
=2×6.5,
=13;
(5)0.625×0.8×0.04×0.5
=(0.625×0.8)×(0.04×0.5),
=0.5×0.02,
=0.01;
(6)18.8×101-18.8
=(101-1)×18.8,
=100×18.8,
=1880.
=47×(0.125×8),
=47×1,
=47;
(2)0.65×201
=0.65×(200+1),
=0.65×200+0.65,
=130+0.65,
=130.65;
(3)0.02×48.8×50
=0.02×50×48.8,
=1×48.8,
=48.8;
(4)1.45×6.5+0.55×6.5
=(1.45+0.55)×6.5,
=2×6.5,
=13;
(5)0.625×0.8×0.04×0.5
=(0.625×0.8)×(0.04×0.5),
=0.5×0.02,
=0.01;
(6)18.8×101-18.8
=(101-1)×18.8,
=100×18.8,
=1880.
点评:本题考查了学生根据乘法运算定律对算式进行简算的能力.
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