题目内容
| 用简便方法计算. 47×
|
17×
| ||||||||
101×
|
(13+
|
分析:(1)(3)(4)根据乘法分配律简便计算;
(2)将除法变为乘法,根据乘法分配律简便计算.
(2)将除法变为乘法,根据乘法分配律简便计算.
解答:解:(1)47×
=(46+1)×
=46×
+
=27+
=27
;
(2)17×
+17÷
=17×
+17×
=17×(
+
)
=17×1
=17;
(3)101×
-
=(101-1)×
=100×
=
;
(4)(13+
)×
=13×
+
×
=2
+
=2
.
| 27 |
| 46 |
=(46+1)×
| 27 |
| 46 |
=46×
| 27 |
| 46 |
| 27 |
| 46 |
=27+
| 27 |
| 46 |
=27
| 27 |
| 46 |
(2)17×
| 11 |
| 23 |
| 23 |
| 12 |
=17×
| 11 |
| 23 |
| 12 |
| 23 |
=17×(
| 11 |
| 23 |
| 12 |
| 23 |
=17×1
=17;
(3)101×
| 3 |
| 7 |
| 3 |
| 7 |
=(101-1)×
| 3 |
| 7 |
=100×
| 3 |
| 7 |
=
| 300 |
| 7 |
(4)(13+
| 4 |
| 5 |
| 5 |
| 26 |
=13×
| 5 |
| 26 |
| 4 |
| 5 |
| 5 |
| 26 |
=2
| 1 |
| 2 |
| 2 |
| 13 |
=2
| 17 |
| 26 |
点评:此题主要考查分数的四则混合运算的运算顺序和运算法则,以及应用运算定律进行简便计算.
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