题目内容
用递等式计算
0.36×
+
÷![数学公式](http://thumb.1010pic.com/pic5/latex/764.png)
-(
-
)-
÷![数学公式](http://thumb.1010pic.com/pic5/latex/13.png)
0.56÷[(3.6×
-1.5)×4.4+5.6].
解:(1)0.36×
+
÷
,
=
+
,
=![](http://thumb.1010pic.com/pic5/latex/517157.png)
,
![](http://thumb.1010pic.com/pic5/latex/517159.png)
,
=
,
=21
;
(2)18
-(
-
)-
÷
,
=18
-5
-
2,
=18
-5
,
=18
5![](http://thumb.1010pic.com/pic5/latex/517166.png)
,
=12
;
(3)0.56÷[(3.6×
-1.5)×4.4+5.6],
=0.56÷[(1.5-1.5)×4.4+5.6],
=0.56÷[0×4.4+5.6],
=0.56÷5.6,
=0.1.
分析:算式(1)把小数化成分数,根据分数四则混合运算的运算顺序.按照分数四则运算的计算法则进行计算;
算式(2),根据分数四则混合运算的运算顺序.按照分数四则运算的计算法则进行计算;
算式(3)根据小数和分数四则混合运算的运算顺序,按照它们的计算法则进行计算.
点评:此题主要考查分数、小数四则混合运算,注意运算顺序和它们的计算法则.
![](http://thumb.1010pic.com/pic5/latex/182951.png)
![](http://thumb.1010pic.com/pic5/latex/182952.png)
![](http://thumb.1010pic.com/pic5/latex/764.png)
=
![](http://thumb.1010pic.com/pic5/latex/517155.png)
![](http://thumb.1010pic.com/pic5/latex/517156.png)
=
![](http://thumb.1010pic.com/pic5/latex/517157.png)
![](http://thumb.1010pic.com/pic5/latex/517158.png)
![](http://thumb.1010pic.com/pic5/latex/517159.png)
![](http://thumb.1010pic.com/pic5/latex/517160.png)
=
![](http://thumb.1010pic.com/pic5/latex/517161.png)
=21
![](http://thumb.1010pic.com/pic5/latex/517162.png)
(2)18
![](http://thumb.1010pic.com/pic5/latex/4442.png)
![](http://thumb.1010pic.com/pic5/latex/182954.png)
![](http://thumb.1010pic.com/pic5/latex/15662.png)
![](http://thumb.1010pic.com/pic5/latex/5882.png)
![](http://thumb.1010pic.com/pic5/latex/13.png)
=18
![](http://thumb.1010pic.com/pic5/latex/4442.png)
![](http://thumb.1010pic.com/pic5/latex/179987.png)
![](http://thumb.1010pic.com/pic5/latex/517163.png)
=18
![](http://thumb.1010pic.com/pic5/latex/4442.png)
![](http://thumb.1010pic.com/pic5/latex/517164.png)
=18
![](http://thumb.1010pic.com/pic5/latex/517165.png)
![](http://thumb.1010pic.com/pic5/latex/517166.png)
![](http://thumb.1010pic.com/pic5/latex/517167.png)
=12
![](http://thumb.1010pic.com/pic5/latex/517168.png)
(3)0.56÷[(3.6×
![](http://thumb.1010pic.com/pic5/latex/927.png)
=0.56÷[(1.5-1.5)×4.4+5.6],
=0.56÷[0×4.4+5.6],
=0.56÷5.6,
=0.1.
分析:算式(1)把小数化成分数,根据分数四则混合运算的运算顺序.按照分数四则运算的计算法则进行计算;
算式(2),根据分数四则混合运算的运算顺序.按照分数四则运算的计算法则进行计算;
算式(3)根据小数和分数四则混合运算的运算顺序,按照它们的计算法则进行计算.
点评:此题主要考查分数、小数四则混合运算,注意运算顺序和它们的计算法则.
![](http://thumb2018.1010pic.com/images/loading.gif)
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