题目内容
选择合理的方法计算: 12×(
|
37×
|
| ||||||||||||||||||||
|
(
|
|
分析:(1)(6)运用乘法分配律简算;
(2)先把37分解成36+1,再运用乘法分配律简算;
(3)(4)按照从左到右的顺序计算;
(5)先把除法变成乘法,再运用乘法分配律简算.
(2)先把37分解成36+1,再运用乘法分配律简算;
(3)(4)按照从左到右的顺序计算;
(5)先把除法变成乘法,再运用乘法分配律简算.
解答:解:(1)12×(
+
),
=12×
+12×
,
=8+2,
=10;
(2)37×
,
=(36+1)×
,
=36×
+1×
,
=5+
,
=5
;
(3)
×
÷
,
=
×
,
=
;
(4)
×
×
,
=
×
,
=
;
(5)(
+
)÷
,
=
×
+
×
,
=
+1,
=2
;
(6)
×
+
×
,
=(
+
)×
,
=1×
,
=
.
2 |
3 |
1 |
6 |
=12×
2 |
3 |
1 |
6 |
=8+2,
=10;
(2)37×
5 |
36 |
=(36+1)×
5 |
36 |
=36×
5 |
36 |
5 |
36 |
=5+
5 |
36 |
=5
5 |
36 |
(3)
7 |
10 |
5 |
16 |
21 |
32 |
=
7 |
32 |
32 |
21 |
=
1 |
3 |
(4)
5 |
12 |
7 |
25 |
3 |
14 |
=
7 |
60 |
3 |
14 |
=
1 |
40 |
(5)(
7 |
8 |
13 |
16 |
13 |
16 |
=
7 |
8 |
16 |
13 |
13 |
16 |
16 |
13 |
=
14 |
13 |
=2
1 |
13 |
(6)
7 |
13 |
3 |
4 |
3 |
4 |
6 |
13 |
=(
7 |
13 |
6 |
13 |
3 |
4 |
=1×
3 |
4 |
=
3 |
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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