题目内容
下面各题怎样算简便就怎样算.
(-)×36 | ||
×+÷ | 2-÷- | . |
解:(1),
=()×16,
=3×16,
=48;
(2)(-)×36,
=×36-×36,
=21-10,
=11;
(3),
=+6,
=6;
(4)×+÷,
=×+×,
=×(+),
=×1,
=;
(5)2-÷-,
=2--,
=2-(+),
=2-1,
=1;
(6),
=+×,
=+,
=.
分析:(1)根据乘法交换律和结合律进行简算;
(2)根据乘法分配律进行简算;
(3)先算除法,再算加法;
(4)根据乘法分配律进行简算;
(5)先算除法,再算减法;
(6)先算小括号内的减法,再算乘法,最后算加法.
点评:四则混合运算,先弄清运算顺序,然后再进行计算,能简算的要简算.
=()×16,
=3×16,
=48;
(2)(-)×36,
=×36-×36,
=21-10,
=11;
(3),
=+6,
=6;
(4)×+÷,
=×+×,
=×(+),
=×1,
=;
(5)2-÷-,
=2--,
=2-(+),
=2-1,
=1;
(6),
=+×,
=+,
=.
分析:(1)根据乘法交换律和结合律进行简算;
(2)根据乘法分配律进行简算;
(3)先算除法,再算加法;
(4)根据乘法分配律进行简算;
(5)先算除法,再算减法;
(6)先算小括号内的减法,再算乘法,最后算加法.
点评:四则混合运算,先弄清运算顺序,然后再进行计算,能简算的要简算.
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