题目内容
计算下面各题,怎样简便就怎样计算.
|
| 6-(
| ||||||||||||||||||
|
| 0.8×(3.2-
|
考点:分数的加法和减法
专题:运算顺序及法则
分析:(1)运用加法结合律简算;
(2)按照从左到右的顺序计算;
(3)先算小括号里面的减法,再算括号外的减法;
(4)根据减法的性质简算;
(5)根据减法的性质简算;
(6)先算小括号里面的减法,再算括号外的减法.
(2)按照从左到右的顺序计算;
(3)先算小括号里面的减法,再算括号外的减法;
(4)根据减法的性质简算;
(5)根据减法的性质简算;
(6)先算小括号里面的减法,再算括号外的减法.
解答:
解:(1)
+
+
+
=
+(
+
+
)
=
+
=
;
(2)
-
+
=
+
=
;
(3)6-(
-
)
=6-
=5
;
(4)
-(
+
)
=
-
-
=
-
=
;
(5)
-
-
-
=
-(
+
+
)
=
-1
=
;
(6)0.8×(3.2-
)
=0.8×3
=2.4.
2 |
3 |
5 |
8 |
3 |
8 |
1 |
8 |
=
2 |
3 |
5 |
8 |
3 |
8 |
1 |
8 |
=
2 |
3 |
9 |
8 |
=
43 |
24 |
(2)
4 |
5 |
3 |
10 |
4 |
15 |
=
1 |
2 |
4 |
15 |
=
23 |
30 |
(3)6-(
3 |
4 |
2 |
5 |
=6-
7 |
20 |
=5
13 |
20 |
(4)
3 |
4 |
3 |
8 |
1 |
4 |
=
3 |
4 |
1 |
4 |
3 |
8 |
=
1 |
2 |
3 |
8 |
=
1 |
8 |
(5)
26 |
25 |
4 |
13 |
5 |
13 |
4 |
13 |
=
26 |
25 |
4 |
13 |
5 |
13 |
4 |
13 |
=
26 |
25 |
=
1 |
25 |
(6)0.8×(3.2-
1 |
5 |
=0.8×3
=2.4.
点评:此题是考查四则混合运算,要仔细观察算式的特点,灵活运用一些定律进行简便计算.
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