题目内容
脱式计算,能简算的要简算
×
+
×
(
+
-
)×24
(
+
)÷
+
.
解:(1)
×
+
×
,
=(
+
)×
,
=1×
,
=
;
(2)(
+
-
)×24,
=
×24+
×24-
×24,
=6+20-16,
=26-16,
=10;
(3)(
+
)÷
+
,
=![](http://thumb.1010pic.com/pic5/latex/41771.png)
+
,
=
+
,
=
.
分析:(1)(2)运用乘法分配律简算;(3)先算小括号里面的加法,再算括号外的除法,最后算加法.
点评:乘法分配律是最常用的简便运算的方法,要熟练掌握,灵活运用.
![](http://thumb.1010pic.com/pic5/latex/764.png)
![](http://thumb.1010pic.com/pic5/latex/9512.png)
![](http://thumb.1010pic.com/pic5/latex/3982.png)
![](http://thumb.1010pic.com/pic5/latex/9512.png)
=(
![](http://thumb.1010pic.com/pic5/latex/764.png)
![](http://thumb.1010pic.com/pic5/latex/3982.png)
![](http://thumb.1010pic.com/pic5/latex/9512.png)
=1×
![](http://thumb.1010pic.com/pic5/latex/9512.png)
=
![](http://thumb.1010pic.com/pic5/latex/9512.png)
(2)(
![](http://thumb.1010pic.com/pic5/latex/96.png)
![](http://thumb.1010pic.com/pic5/latex/155.png)
![](http://thumb.1010pic.com/pic5/latex/168.png)
=
![](http://thumb.1010pic.com/pic5/latex/96.png)
![](http://thumb.1010pic.com/pic5/latex/155.png)
![](http://thumb.1010pic.com/pic5/latex/168.png)
=6+20-16,
=26-16,
=10;
(3)(
![](http://thumb.1010pic.com/pic5/latex/602.png)
![](http://thumb.1010pic.com/pic5/latex/96.png)
![](http://thumb.1010pic.com/pic5/latex/317.png)
![](http://thumb.1010pic.com/pic5/latex/3724.png)
=
![](http://thumb.1010pic.com/pic5/latex/41771.png)
![](http://thumb.1010pic.com/pic5/latex/214730.png)
![](http://thumb.1010pic.com/pic5/latex/3724.png)
=
![](http://thumb.1010pic.com/pic5/latex/3662.png)
![](http://thumb.1010pic.com/pic5/latex/3724.png)
=
![](http://thumb.1010pic.com/pic5/latex/10142.png)
分析:(1)(2)运用乘法分配律简算;(3)先算小括号里面的加法,再算括号外的除法,最后算加法.
点评:乘法分配律是最常用的简便运算的方法,要熟练掌握,灵活运用.
![](http://thumb2018.1010pic.com/images/loading.gif)
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