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.
练习册系列答案
相关题目