题目内容
怎样简便就怎么算
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|
|
|
分析:(1)运用加法交换律解答,
(2)依据减法性质解答,
(3)运用加法交换律和结合律解答,
(4)按照先算括号里面的加法,再算括号外面的减法解答.
(2)依据减法性质解答,
(3)运用加法交换律和结合律解答,
(4)按照先算括号里面的加法,再算括号外面的减法解答.
解答:解:(1)
-
+
,
=(
+
)-
,
=1-
,
=
;
(2)
-
-
,
=
-(
+
),
=
-
,
=0;
(3)
+
+
+
,
=(
+
)+(
+
),
=
+
,
=2
;
(4)
-(
+0.25),
=
-
,
=
.
4 |
9 |
1 |
3 |
5 |
9 |
=(
4 |
9 |
5 |
9 |
1 |
3 |
=1-
1 |
3 |
=
2 |
3 |
(2)
8 |
15 |
1 |
5 |
1 |
3 |
=
8 |
15 |
1 |
5 |
1 |
3 |
=
8 |
15 |
8 |
15 |
=0;
(3)
3 |
4 |
1 |
12 |
7 |
12 |
3 |
4 |
=(
3 |
4 |
3 |
4 |
1 |
12 |
7 |
12 |
=
3 |
2 |
2 |
3 |
=2
1 |
6 |
(4)
5 |
8 |
1 |
3 |
=
5 |
8 |
7 |
12 |
=
1 |
24 |
点评:本题主要考查学生依据四则运算顺序,以及正确运用简便算法解决问题的能力.

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