题目内容
计算下列各题,怎样算简便就怎样算. 3-
|
| ||||||||||||
|
| ||||||||||||
|
2-[
|
分析:(1)(3)依据减法性质解答,
(2)运用加法交换律和加法结合律解答,
(4)(5)(6)依据四则运算计算方法:先算第二级运算,再算第一级运算,如果只含有同一级运算,按照从左到右顺序计算,有括号先算括号里面的解答.
(2)运用加法交换律和加法结合律解答,
(4)(5)(6)依据四则运算计算方法:先算第二级运算,再算第一级运算,如果只含有同一级运算,按照从左到右顺序计算,有括号先算括号里面的解答.
解答:解:(1)3-
-
,
=3-(
+
),
=3-1,
=2;
(2)
+
-
+
,
=(
-
)+(
+
),
=0+1,
=1;
(3)
-(
-
),
=
+
-
,
=1-
,
=
;
(4)
+(
-
),
=
+
,
=
;
(5)
-(
+
),
=
-
,
=
;
(6)2-[
-(
+
)],
=2-[
-
],
=2-0,
=2.
7 |
11 |
4 |
11 |
=3-(
7 |
11 |
4 |
11 |
=3-1,
=2;
(2)
7 |
8 |
3 |
4 |
7 |
8 |
1 |
4 |
=(
7 |
8 |
7 |
8 |
3 |
4 |
1 |
4 |
=0+1,
=1;
(3)
5 |
9 |
8 |
17 |
4 |
9 |
=
5 |
9 |
4 |
9 |
8 |
17 |
=1-
8 |
17 |
=
9 |
17 |
(4)
2 |
5 |
5 |
6 |
1 |
3 |
=
2 |
5 |
1 |
2 |
=
9 |
10 |
(5)
2 |
3 |
1 |
12 |
1 |
4 |
=
2 |
3 |
1 |
3 |
=
1 |
3 |
(6)2-[
17 |
60 |
2 |
15 |
3 |
20 |
=2-[
17 |
60 |
17 |
60 |
=2-0,
=2.
点评:本题主要考查学生依据四则运算计算方法,以及正确运用简便算法解决问题的能力.
练习册系列答案
相关题目