题目内容
3×
+2.7×25%
×11.6+18.4×![数学公式](http://thumb.1010pic.com/pic5/latex/3086.png)
×
-60%×![数学公式](http://thumb.1010pic.com/pic5/latex/28406.png)
×31+![数学公式](http://thumb.1010pic.com/pic5/latex/15299.png)
×
+
÷![数学公式](http://thumb.1010pic.com/pic5/latex/70630.png)
×38.
解:(1)3×
+2.7×25%
=3×
+2.7×
=(3+2.7)×
=5.7×![](http://thumb.1010pic.com/pic5/latex/96.png)
=
×![](http://thumb.1010pic.com/pic5/latex/96.png)
=
;
(2)
×11.6+18.4×![](http://thumb.1010pic.com/pic5/latex/3086.png)
=
×(11.6+18.4)
=
×30
=54;
(3)
×
-60%×![](http://thumb.1010pic.com/pic5/latex/28406.png)
=(
-60%)×![](http://thumb.1010pic.com/pic5/latex/28406.png)
=(
-
)×![](http://thumb.1010pic.com/pic5/latex/28406.png)
=
×![](http://thumb.1010pic.com/pic5/latex/28406.png)
=
;
(4)
×31+![](http://thumb.1010pic.com/pic5/latex/15299.png)
=
×(31+1)
=
×32
=7;
(5)
×
+
÷![](http://thumb.1010pic.com/pic5/latex/70630.png)
=
×
+
×![](http://thumb.1010pic.com/pic5/latex/27433.png)
=(
+
)×![](http://thumb.1010pic.com/pic5/latex/168.png)
=1×![](http://thumb.1010pic.com/pic5/latex/168.png)
=
;
(6)
×38
=
×(37+1)
=
×37+![](http://thumb.1010pic.com/pic5/latex/315576.png)
=33+![](http://thumb.1010pic.com/pic5/latex/315576.png)
=33
.
分析:(1)把百分数化为分数,运用乘法分配律简算;
(2)(3)(4)运用乘法分配律简算;
(5)把除法改为乘法,运用乘法分配律简算;
(6)把38看做37+1,运用乘法分配律简算.
点评:此题主要考查了乘法分配律的灵活运用.
![](http://thumb.1010pic.com/pic5/latex/96.png)
=3×
![](http://thumb.1010pic.com/pic5/latex/96.png)
![](http://thumb.1010pic.com/pic5/latex/96.png)
=(3+2.7)×
![](http://thumb.1010pic.com/pic5/latex/96.png)
=5.7×
![](http://thumb.1010pic.com/pic5/latex/96.png)
=
![](http://thumb.1010pic.com/pic5/latex/204455.png)
![](http://thumb.1010pic.com/pic5/latex/96.png)
=
![](http://thumb.1010pic.com/pic5/latex/315577.png)
(2)
![](http://thumb.1010pic.com/pic5/latex/3086.png)
![](http://thumb.1010pic.com/pic5/latex/3086.png)
=
![](http://thumb.1010pic.com/pic5/latex/3086.png)
=
![](http://thumb.1010pic.com/pic5/latex/3086.png)
=54;
(3)
![](http://thumb.1010pic.com/pic5/latex/1086.png)
![](http://thumb.1010pic.com/pic5/latex/28406.png)
![](http://thumb.1010pic.com/pic5/latex/28406.png)
=(
![](http://thumb.1010pic.com/pic5/latex/1086.png)
![](http://thumb.1010pic.com/pic5/latex/28406.png)
=(
![](http://thumb.1010pic.com/pic5/latex/1086.png)
![](http://thumb.1010pic.com/pic5/latex/14.png)
![](http://thumb.1010pic.com/pic5/latex/28406.png)
=
![](http://thumb.1010pic.com/pic5/latex/24927.png)
![](http://thumb.1010pic.com/pic5/latex/28406.png)
=
![](http://thumb.1010pic.com/pic5/latex/1412.png)
(4)
![](http://thumb.1010pic.com/pic5/latex/15299.png)
![](http://thumb.1010pic.com/pic5/latex/15299.png)
=
![](http://thumb.1010pic.com/pic5/latex/15299.png)
=
![](http://thumb.1010pic.com/pic5/latex/15299.png)
=7;
(5)
![](http://thumb.1010pic.com/pic5/latex/22186.png)
![](http://thumb.1010pic.com/pic5/latex/168.png)
![](http://thumb.1010pic.com/pic5/latex/168.png)
![](http://thumb.1010pic.com/pic5/latex/70630.png)
=
![](http://thumb.1010pic.com/pic5/latex/22186.png)
![](http://thumb.1010pic.com/pic5/latex/168.png)
![](http://thumb.1010pic.com/pic5/latex/168.png)
![](http://thumb.1010pic.com/pic5/latex/27433.png)
=(
![](http://thumb.1010pic.com/pic5/latex/22186.png)
![](http://thumb.1010pic.com/pic5/latex/27433.png)
![](http://thumb.1010pic.com/pic5/latex/168.png)
=1×
![](http://thumb.1010pic.com/pic5/latex/168.png)
=
![](http://thumb.1010pic.com/pic5/latex/168.png)
(6)
![](http://thumb.1010pic.com/pic5/latex/315576.png)
=
![](http://thumb.1010pic.com/pic5/latex/315576.png)
=
![](http://thumb.1010pic.com/pic5/latex/315576.png)
![](http://thumb.1010pic.com/pic5/latex/315576.png)
=33+
![](http://thumb.1010pic.com/pic5/latex/315576.png)
=33
![](http://thumb.1010pic.com/pic5/latex/315576.png)
分析:(1)把百分数化为分数,运用乘法分配律简算;
(2)(3)(4)运用乘法分配律简算;
(5)把除法改为乘法,运用乘法分配律简算;
(6)把38看做37+1,运用乘法分配律简算.
点评:此题主要考查了乘法分配律的灵活运用.
![](http://thumb2018.1010pic.com/images/loading.gif)
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