题目内容
用简便方法计算下面各题.
(1)
×41
(2)2011×
.
(1)
| 54 |
| 55 |
(2)2011×
| 19 |
| 2010 |
分析:(1)
=1-
,然后再根据乘法分配律进行简算;
(2)2011=2010+1,然后再根据乘法分配律进行简算.
| 54 |
| 55 |
| 1 |
| 55 |
(2)2011=2010+1,然后再根据乘法分配律进行简算.
解答:解:
(1)
×41,
=(1-
)×41,
=1×41-
×41,
=41-
,
=40
;
(2)2011×
,
=(2010+1)×
,
=2010×
+1×
,
=19+
,
=19
.
(1)
| 54 |
| 55 |
=(1-
| 1 |
| 55 |
=1×41-
| 1 |
| 55 |
=41-
| 41 |
| 55 |
=40
| 14 |
| 55 |
(2)2011×
| 19 |
| 2010 |
=(2010+1)×
| 19 |
| 2010 |
=2010×
| 19 |
| 2010 |
| 19 |
| 2010 |
=19+
| 19 |
| 2010 |
=19
| 19 |
| 2010 |
点评:此题主要考查分数的四则混合运算的运算顺序和应用运算定律进行简便计算.
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