题目内容
简便计算
43×99+43 | -+- | ×-÷13 |
3.5×98+35×0.2 | 250×+250× | ×12.5××8. |
解:(1)43×99+43,
=43×(99+1),
=43×100,
=4300;
(2)-+-,
=(+)-(+),
=1-1,
=0;
(3)×-÷13,
=×-×,
=(-)×,
=×,
=;
(4)3.5×98+35×0.2,
=3.5×98+3.5×2,
=3.5×(98+2),
=3.5×100,
=350;
(5)250×+250×,
=250×(+),
=250×1,
=250;
(6)×12.5××8,
=(×)×(12.5×8),
=×100,
=330.
分析:(1)根据乘法分配律进行简算;
(2)根据加法交换律和结合律进行简算;
(3)根据乘法分配律进行简算;
(4)根据乘法分配律进行简算;
(5)根据乘法分配律进行简算;
(6)根据乘法交换律和结合律进行简算.
点评:根据题意,找准所运用的运算定律,然后再进一步简算即可.
=43×(99+1),
=43×100,
=4300;
(2)-+-,
=(+)-(+),
=1-1,
=0;
(3)×-÷13,
=×-×,
=(-)×,
=×,
=;
(4)3.5×98+35×0.2,
=3.5×98+3.5×2,
=3.5×(98+2),
=3.5×100,
=350;
(5)250×+250×,
=250×(+),
=250×1,
=250;
(6)×12.5××8,
=(×)×(12.5×8),
=×100,
=330.
分析:(1)根据乘法分配律进行简算;
(2)根据加法交换律和结合律进行简算;
(3)根据乘法分配律进行简算;
(4)根据乘法分配律进行简算;
(5)根据乘法分配律进行简算;
(6)根据乘法交换律和结合律进行简算.
点评:根据题意,找准所运用的运算定律,然后再进一步简算即可.
练习册系列答案
相关题目