题目内容
用简便方法计算.
(1)
×4+
×2+
×16
(2)
×2012.
(1)
| 4 |
| 5 |
| 2 |
| 5 |
| 1 |
| 5 |
(2)
| 2012 |
| 2013 |
分析:(1)可根据分配律计算;
(2)可将2012变主2013-1后根据乘法分配律计算.
(2)可将2012变主2013-1后根据乘法分配律计算.
解答:解:(1)
×4+
×2+
×16
=
×4+
×4+
×4,
=(
+
+
)×4,
=
×4,
=
;
(2)
×2012
=
×(2013-1)
=
×2013-
,
=2012-
,
=2011
.
| 4 |
| 5 |
| 2 |
| 5 |
| 1 |
| 5 |
=
| 4 |
| 5 |
| 1 |
| 5 |
| 4 |
| 5 |
=(
| 4 |
| 5 |
| 1 |
| 5 |
| 4 |
| 5 |
=
| 9 |
| 5 |
=
| 36 |
| 5 |
(2)
| 2012 |
| 2013 |
=
| 2012 |
| 2013 |
=
| 2012 |
| 2013 |
| 2012 |
| 2013 |
=2012-
| 2012 |
| 2013 |
=2011
| 1 |
| 2013 |
点评:完成此类题要细心分析题目中的数据,然后运用合适的方法计算.
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