题目内容
简便计算.
2.5×32×1.25 | (
|
|
分析:(1)可将32拆分为4×8后,根据乘法结合律计算;
(2)(3)可将除法算式变为乘法算式后,根据乘法分配律计算;
(2)(3)可将除法算式变为乘法算式后,根据乘法分配律计算;
解答:解:(1)2.5×32×1.25
=(2.5×4)×(8×1.25),
=10×10,
=100;
(2)(
+
-
)÷
=(
+
-
)×24,
=
×24+
×24-
×24,
=10+20-9,
=21;
(3)
×
+
÷
-
=
×
+
×
-
,
=(
+
-1)×
,
=
×
,
=
.
=(2.5×4)×(8×1.25),
=10×10,
=100;
(2)(
5 |
12 |
5 |
6 |
3 |
8 |
1 |
24 |
=(
5 |
12 |
5 |
6 |
3 |
8 |
=
5 |
12 |
5 |
6 |
3 |
8 |
=10+20-9,
=21;
(3)
7 |
19 |
6 |
7 |
13 |
19 |
7 |
6 |
6 |
7 |
=
7 |
19 |
6 |
7 |
13 |
19 |
6 |
7 |
6 |
7 |
=(
7 |
19 |
13 |
19 |
6 |
7 |
=
1 |
19 |
6 |
7 |
=
6 |
133 |
点评:完成本题要细心分析式中数据,然后运用合适的方法计算.
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