题目内容
用自己喜欢的方法计算: 12-
|
76×
|
(
|
|
分析:(1)把除法改为乘法,运用加法结合律简算;
(2)把76看作77-1,运用乘法分配律简算;
(3)根据数字特点,运用乘法分配律简算;
(4)把除法改为乘法,运用乘法分配律简算.
(2)把76看作77-1,运用乘法分配律简算;
(3)根据数字特点,运用乘法分配律简算;
(4)把除法改为乘法,运用乘法分配律简算.
解答:解:(1)12-
+
÷
,
=12-
+
×5,
=12+(
-
),
=12+
,
=12
;
(2)76×
,
=(77-1)×
,
=77×
-
,
=76-
,
=75
;
(3)(
+
)×5×7,
=
×5×7+
×5×7,
=14+30,
=44;
(4)
÷7+
×
,
=
×
+
×
,
=(
+
)×
,
=1×
,
=
.
2 |
7 |
1 |
7 |
1 |
5 |
=12-
2 |
7 |
1 |
7 |
=12+(
5 |
7 |
2 |
7 |
=12+
3 |
7 |
=12
3 |
7 |
(2)76×
76 |
77 |
=(77-1)×
76 |
77 |
=77×
76 |
77 |
76 |
77 |
=76-
76 |
77 |
=75
1 |
77 |
(3)(
2 |
5 |
6 |
7 |
=
2 |
5 |
6 |
7 |
=14+30,
=44;
(4)
5 |
12 |
7 |
12 |
1 |
7 |
=
5 |
12 |
1 |
7 |
7 |
12 |
1 |
7 |
=(
5 |
12 |
7 |
12 |
1 |
7 |
=1×
1 |
7 |
=
1 |
7 |
点评:完成本题要注意分析式中数据,运用合适的简便方法计算.
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