题目内容
| 用简便方法计算 527+199 |
735-198 | 105×99 | 865-198 |
| 75×98 | 68×99+68 | 63×88+88×37 | 58×99+58 |
考点:运算定律与简便运算
专题:运算定律及简算
分析:(1)把199看作200-1,然后再计算;
(2)把198看作200-2,然后再计算;
(3)把99看作100-1,然后再根据乘法分配律进行简算;
(4)把198看作200-2,然后再计算;
(5)把98看作100-2,然后再根据乘法分配律进行简算;
(6)根据乘法分配律进行简算;
(7)根据乘法分配律进行简算;
(8)根据乘法分配律进行简算.
(2)把198看作200-2,然后再计算;
(3)把99看作100-1,然后再根据乘法分配律进行简算;
(4)把198看作200-2,然后再计算;
(5)把98看作100-2,然后再根据乘法分配律进行简算;
(6)根据乘法分配律进行简算;
(7)根据乘法分配律进行简算;
(8)根据乘法分配律进行简算.
解答:
解:(1)527+199
=527+(200-1)
=527+200-1
=727-1
=726;
(2)735-198
=735-(200-2)
=735-200+2
=535+2
=537;
(3)105×99
=105×(100-1)
=105×100-105×1
=10500-105
=10395;
(4)865-198
=865-(200-2)
=865-200+2
=665+2
=667;
(5)75×98
=75×(100-2)
=75×100-75×2
=7500-150
=7350;
(6)68×99+68
=68×(99+1)
=68×100
=6800;
(7)63×88+88×37
=(63+37)×88
=100×88
=8800;
(8)58×99+58
=58×(99+1)
=58×100
=5800.
=527+(200-1)
=527+200-1
=727-1
=726;
(2)735-198
=735-(200-2)
=735-200+2
=535+2
=537;
(3)105×99
=105×(100-1)
=105×100-105×1
=10500-105
=10395;
(4)865-198
=865-(200-2)
=865-200+2
=665+2
=667;
(5)75×98
=75×(100-2)
=75×100-75×2
=7500-150
=7350;
(6)68×99+68
=68×(99+1)
=68×100
=6800;
(7)63×88+88×37
=(63+37)×88
=100×88
=8800;
(8)58×99+58
=58×(99+1)
=58×100
=5800.
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.
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