题目内容
脱式计算(能简便的要简便运算).
|
2-
|
| ||||||||||||||||||||
|
24×(
|
|
分析:(1)运用加法交换律、结合律进行简算,
(2)先算除法,再从左向右进行计算,
(3)把除以
化成乘以
,直接约分计算,
(4)先算运用减法的性质简算小括号里的减法,再算括号外的除法,
(5)运用乘法的分配律进行简算,
(6)运用乘法的分配律进行简算.
(2)先算除法,再从左向右进行计算,
(3)把除以
22 |
3 |
3 |
22 |
(4)先算运用减法的性质简算小括号里的减法,再算括号外的除法,
(5)运用乘法的分配律进行简算,
(6)运用乘法的分配律进行简算.
解答:解:(1)
+
+
+
,
=(
+
)+(
+
),
=1+1,
=2;
(2)2-
÷
-
,
=2-
-
,
=
-
,
=
;
(3)
÷
×
,
=
×
×
,
=
;
(4)
÷(3-
-
),
=
÷[3-(
+
)],
=
÷[3-1],
=
÷2,
=
;
(5)24×(
+
-
),
=24×
+24×
-24×
,
=8+6-12,
=14-12,
=2;
(6)
×
+
×
,
=(
+
)×
,
=1×
,
=
.
7 |
12 |
4 |
9 |
5 |
12 |
5 |
9 |
=(
7 |
12 |
5 |
12 |
4 |
9 |
5 |
9 |
=1+1,
=2;
(2)2-
5 |
13 |
9 |
26 |
2 |
3 |
=2-
10 |
9 |
2 |
3 |
=
8 |
9 |
2 |
3 |
=
2 |
9 |
(3)
11 |
7 |
22 |
3 |
14 |
15 |
=
11 |
7 |
3 |
22 |
14 |
15 |
=
1 |
5 |
(4)
1 |
4 |
5 |
13 |
8 |
13 |
=
1 |
4 |
5 |
13 |
8 |
13 |
=
1 |
4 |
=
1 |
4 |
=
1 |
8 |
(5)24×(
1 |
3 |
1 |
4 |
1 |
2 |
=24×
1 |
3 |
1 |
4 |
1 |
2 |
=8+6-12,
=14-12,
=2;
(6)
5 |
8 |
4 |
9 |
4 |
9 |
3 |
8 |
=(
5 |
8 |
3 |
8 |
4 |
9 |
=1×
4 |
9 |
=
4 |
9 |
点评:考查了分数四则混合运算的顺序,注意灵活运用运算定律进行简算.
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