题目内容
简便计算
99+101+297+3 | 125×32×25 | 156×101-156 |
99×67 | 5620-562-438 | 1300÷25÷4. |
解:(1)99+101+297+3,
=(99+101)+(297+3),
=200+300,
=500;
(2)125×32×25,
=125×(4×8)×25,
=(125×8)×(25×4),
=1000×100,
=100000;
(3)156×101-156,
=156×(l0l-1),
=156×100,
=15600;
(4)99×67,
=(100-1)×67,
=100×67-1×67,
=6700-67,
=6633;
(5)5620-562-438,
=5620-(562+438),
=5620-1000,
=4620;
(6)1300÷25÷4,
=1300÷(25×4),
=1300÷100,
=13.
分析:(1)根据加法交换律和结合律进行计算;
(2)根据乘法交换律和结合律进行计算;
(3)根据乘法分配律进行计算;
(4)根据乘法分配律进行计算;
(5)根据连减的性质进行计算;
(6)根据连除的性质进行计算.
点评:根据题意,找准所运用的运算定律,然后再进一步计算即可.
=(99+101)+(297+3),
=200+300,
=500;
(2)125×32×25,
=125×(4×8)×25,
=(125×8)×(25×4),
=1000×100,
=100000;
(3)156×101-156,
=156×(l0l-1),
=156×100,
=15600;
(4)99×67,
=(100-1)×67,
=100×67-1×67,
=6700-67,
=6633;
(5)5620-562-438,
=5620-(562+438),
=5620-1000,
=4620;
(6)1300÷25÷4,
=1300÷(25×4),
=1300÷100,
=13.
分析:(1)根据加法交换律和结合律进行计算;
(2)根据乘法交换律和结合律进行计算;
(3)根据乘法分配律进行计算;
(4)根据乘法分配律进行计算;
(5)根据连减的性质进行计算;
(6)根据连除的性质进行计算.
点评:根据题意,找准所运用的运算定律,然后再进一步计算即可.
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