题目内容
计算(要求脱式计算)
(1)(27×1
+6
×27)×1.25
(2)〔2-(5.55×1
-2
÷0.4)〕÷0.135.
解:(1)(27×1
+6
×27)×1.25
=(1
+6
)×27×1.25,
=8×1.25×27,
=10×27,
=270;
(2)[2-(5.55×1
-2
÷0.4)]÷0.135
=[2-(5.55×
-2.7÷0.4)]÷0.135,
=[2-(7.4-6.75)]÷0.135,
=[2-0.65]÷0.135,
=1.35÷0.135,
=10.
分析:(1)可运用乘法分配律及交换律计算;
(2)根据四则混合运算的运算顺序计算即可.
点评:当算式中同时含有小数与分数时,要根据式中数据的特点灵活将它们互化后进行计算.
![](http://thumb.1010pic.com/pic5/latex/2766.png)
![](http://thumb.1010pic.com/pic5/latex/4442.png)
=(1
![](http://thumb.1010pic.com/pic5/latex/2766.png)
![](http://thumb.1010pic.com/pic5/latex/4442.png)
=8×1.25×27,
=10×27,
=270;
(2)[2-(5.55×1
![](http://thumb.1010pic.com/pic5/latex/8.png)
![](http://thumb.1010pic.com/pic5/latex/3724.png)
=[2-(5.55×
![](http://thumb.1010pic.com/pic5/latex/304.png)
=[2-(7.4-6.75)]÷0.135,
=[2-0.65]÷0.135,
=1.35÷0.135,
=10.
分析:(1)可运用乘法分配律及交换律计算;
(2)根据四则混合运算的运算顺序计算即可.
点评:当算式中同时含有小数与分数时,要根据式中数据的特点灵活将它们互化后进行计算.
![](http://thumb2018.1010pic.com/images/loading.gif)
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