题目内容
脱式计算. (1)1500-450÷18×25 |
(2)7.6×3.8+7.6×5.2+7.6 | (3)(
| ||||||||||||||||
(4)22×34×
|
(5)19-
|
(6)
|
分析:(1)(6)根据四则混合运算的运算顺序计算即可:先算乘除,再算加减,有括号的要先算括号里面的;
(2)(3)可根据乘法分配律计算;
(4)可根据乘法交换律及交换律计算即可;
(5)可根据加法交换律及一个数减两个数,等于减去这两个数的和的减法性质计算.
(2)(3)可根据乘法分配律计算;
(4)可根据乘法交换律及交换律计算即可;
(5)可根据加法交换律及一个数减两个数,等于减去这两个数的和的减法性质计算.
解答:解:(1)1500-450÷18×25
=1500-25×25,
=1500-625,
=875;
(2)7.6×3.8+7.6×5.2+7.6
=(3.8+5.2+1)×7.6,
=10×7.6,
=76;
(3)(
+
)×35+
=
×35+
×35+
,
=25+28+
,
=53
;
(4)22×34×
×
=(22×
)×(34×
),
=10×8,
=80;
(5)19-
+11-
=(19+11)-(
+
),
=30-1,
=29;
(6)
÷[
×(
+
)]
=
÷[
×
],
=
÷
=
.
=1500-25×25,
=1500-625,
=875;
(2)7.6×3.8+7.6×5.2+7.6
=(3.8+5.2+1)×7.6,
=10×7.6,
=76;
(3)(
5 |
7 |
4 |
5 |
3 |
4 |
=
5 |
7 |
4 |
5 |
3 |
4 |
=25+28+
3 |
4 |
=53
3 |
4 |
(4)22×34×
5 |
11 |
4 |
17 |
=(22×
5 |
11 |
4 |
17 |
=10×8,
=80;
(5)19-
13 |
20 |
7 |
20 |
=(19+11)-(
13 |
20 |
7 |
20 |
=30-1,
=29;
(6)
9 |
20 |
1 |
2 |
2 |
5 |
3 |
4 |
=
9 |
20 |
1 |
2 |
23 |
20 |
=
9 |
20 |
23 |
40 |
=
18 |
23 |
点评:完成本题要注意分析式中数据的特点及内在联系,然后运用合适的方法计算.
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