题目内容
(2011?新泰市)
| 用简便方法计算下面各题.(写出计算过程) ①25×
|
②3×
|
③12×(
|
分析:①运用乘法交换律与结合律简算;
②把除法转化为乘法,运用乘法分配律简算;
③运用乘法分配律简算.
②把除法转化为乘法,运用乘法分配律简算;
③运用乘法分配律简算.
解答:解:①25×
×4×
,
=25×4×(
×
),
=100×
,
=10;
②3×
+4÷
,
=3×
+4×
,
=(3+4)×
,
=7×
,
=3;
③12×(
+
-
),
=12×
+12×
-12×
,
=3+2-4,
=1.
| 1 |
| 3 |
| 3 |
| 10 |
=25×4×(
| 1 |
| 3 |
| 3 |
| 10 |
=100×
| 1 |
| 10 |
=10;
②3×
| 3 |
| 7 |
| 7 |
| 3 |
=3×
| 3 |
| 7 |
| 3 |
| 7 |
=(3+4)×
| 3 |
| 7 |
=7×
| 3 |
| 7 |
=3;
③12×(
| 1 |
| 4 |
| 1 |
| 6 |
| 1 |
| 3 |
=12×
| 1 |
| 4 |
| 1 |
| 6 |
| 1 |
| 3 |
=3+2-4,
=1.
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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