题目内容
怎样简便就怎样算.![]() ![]() ![]() | ![]() ![]() ![]() ![]() |
(![]() ![]() ![]() | ![]() ![]() ![]() |
![]() ![]() ![]() ![]() | ![]() ![]() ![]() |
解:(1)
÷7+
×
,
,
=(
)×
,
=
,
=
;
(2)
×
+
÷
,
=
,
=
2,
=
;
(3)(
+
+
)×24,
=24×
24×
24×
,
=12+16+18,
=46;
(4)
-
÷
,
=
,
=
,
,
=
;
(5)
+
-
+
,
=
+(
),
=0
,
=
;
(6)
÷
÷
.
=
,
=
,
=
.
分析:(1)
÷7+
×
,把除数转化为乘它的倒数,再运用乘法分配律进行简算;
(2)
×
+
÷
,根据分数四则混合运算的顺序,按照分数四则运算的计算法则进行计算;
(3)(
+
+
)×24,运用乘法分配律进行简算;
(4)
-
÷
,根据分数四则混合运算的顺序,按照分数四则运算的计算法则进行计算;
(5)
+
-
+
,根据加、减法的运算性质和加法结合律进行简算;
(6)
÷
÷
.把除数转化为乘它的倒数,然后按照分数乘法的计算法则进行计算.
点评:此题考查的目的是使学生掌握分数四则混合运算的顺序和它们的计算法则,并且能够灵活选择简便方法进行计算.
![](http://thumb.1010pic.com/pic5/latex/5882.png)
![](http://thumb.1010pic.com/pic5/latex/847.png)
![](http://thumb.1010pic.com/pic5/latex/14169.png)
![](http://thumb.1010pic.com/pic5/latex/207441.png)
=(
![](http://thumb.1010pic.com/pic5/latex/207442.png)
![](http://thumb.1010pic.com/pic5/latex/847.png)
=
![](http://thumb.1010pic.com/pic5/latex/207443.png)
=
![](http://thumb.1010pic.com/pic5/latex/62807.png)
(2)
![](http://thumb.1010pic.com/pic5/latex/13.png)
![](http://thumb.1010pic.com/pic5/latex/335.png)
![](http://thumb.1010pic.com/pic5/latex/2105.png)
![](http://thumb.1010pic.com/pic5/latex/3662.png)
=
![](http://thumb.1010pic.com/pic5/latex/207444.png)
=
![](http://thumb.1010pic.com/pic5/latex/207445.png)
=
![](http://thumb.1010pic.com/pic5/latex/203658.png)
(3)(
![](http://thumb.1010pic.com/pic5/latex/13.png)
![](http://thumb.1010pic.com/pic5/latex/168.png)
![](http://thumb.1010pic.com/pic5/latex/365.png)
=24×
![](http://thumb.1010pic.com/pic5/latex/88050.png)
![](http://thumb.1010pic.com/pic5/latex/207446.png)
![](http://thumb.1010pic.com/pic5/latex/365.png)
=12+16+18,
=46;
(4)
![](http://thumb.1010pic.com/pic5/latex/2105.png)
![](http://thumb.1010pic.com/pic5/latex/5192.png)
![](http://thumb.1010pic.com/pic5/latex/155.png)
=
![](http://thumb.1010pic.com/pic5/latex/207447.png)
=
![](http://thumb.1010pic.com/pic5/latex/207448.png)
![](http://thumb.1010pic.com/pic5/latex/207449.png)
=
![](http://thumb.1010pic.com/pic5/latex/3856.png)
(5)
![](http://thumb.1010pic.com/pic5/latex/729.png)
![](http://thumb.1010pic.com/pic5/latex/2131.png)
![](http://thumb.1010pic.com/pic5/latex/729.png)
![](http://thumb.1010pic.com/pic5/latex/2131.png)
=
![](http://thumb.1010pic.com/pic5/latex/207450.png)
![](http://thumb.1010pic.com/pic5/latex/207451.png)
=0
![](http://thumb.1010pic.com/pic5/latex/207452.png)
=
![](http://thumb.1010pic.com/pic5/latex/8064.png)
(6)
![](http://thumb.1010pic.com/pic5/latex/13.png)
![](http://thumb.1010pic.com/pic5/latex/25180.png)
![](http://thumb.1010pic.com/pic5/latex/25181.png)
=
![](http://thumb.1010pic.com/pic5/latex/207453.png)
=
![](http://thumb.1010pic.com/pic5/latex/33.png)
=
![](http://thumb.1010pic.com/pic5/latex/1205.png)
分析:(1)
![](http://thumb.1010pic.com/pic5/latex/5882.png)
![](http://thumb.1010pic.com/pic5/latex/847.png)
![](http://thumb.1010pic.com/pic5/latex/14169.png)
(2)
![](http://thumb.1010pic.com/pic5/latex/13.png)
![](http://thumb.1010pic.com/pic5/latex/335.png)
![](http://thumb.1010pic.com/pic5/latex/2105.png)
![](http://thumb.1010pic.com/pic5/latex/3662.png)
(3)(
![](http://thumb.1010pic.com/pic5/latex/13.png)
![](http://thumb.1010pic.com/pic5/latex/168.png)
![](http://thumb.1010pic.com/pic5/latex/365.png)
(4)
![](http://thumb.1010pic.com/pic5/latex/2105.png)
![](http://thumb.1010pic.com/pic5/latex/5192.png)
![](http://thumb.1010pic.com/pic5/latex/155.png)
(5)
![](http://thumb.1010pic.com/pic5/latex/729.png)
![](http://thumb.1010pic.com/pic5/latex/2131.png)
![](http://thumb.1010pic.com/pic5/latex/729.png)
![](http://thumb.1010pic.com/pic5/latex/2131.png)
(6)
![](http://thumb.1010pic.com/pic5/latex/13.png)
![](http://thumb.1010pic.com/pic5/latex/25180.png)
![](http://thumb.1010pic.com/pic5/latex/25181.png)
点评:此题考查的目的是使学生掌握分数四则混合运算的顺序和它们的计算法则,并且能够灵活选择简便方法进行计算.
![](http://thumb2018.1010pic.com/images/loading.gif)
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