题目内容
(2011?连山区)
脱式计算. 101×9.7-9.7 |
69×0.75+31×75% | 32×19×125 | (
|
分析:算式(1)据乘法分配律变为9.7×(101-1)进行计算;
算式(2)、(4)可据乘法分配律进行计算;
算式(3)可将32拆分为8×4后再据乘法交换律及结合律计算;
算式(2)、(4)可据乘法分配律进行计算;
算式(3)可将32拆分为8×4后再据乘法交换律及结合律计算;
解答:解:(1)101×9.7-9.7,
=9.7×(101-1),
=9.7×100,
=970;
(2)69×0.75+31×75%,
=0.75×(69+31),
=0.75×100,
=75;
(3)32×19×125,
=4×8×19×125,
=(8×125)×(4×19),
=1000×76,
=76000;
(4)(
-
)×45,
=45×
-45×
,
=15-9,
=6.
=9.7×(101-1),
=9.7×100,
=970;
(2)69×0.75+31×75%,
=0.75×(69+31),
=0.75×100,
=75;
(3)32×19×125,
=4×8×19×125,
=(8×125)×(4×19),
=1000×76,
=76000;
(4)(
1 |
3 |
1 |
5 |
=45×
1 |
3 |
1 |
5 |
=15-9,
=6.
点评:完成本题要注意分析式中数据,运用合适的简便方法计算.
练习册系列答案
相关题目