题目内容
| 简算: 2.5×32×12.5 |
8×5×(
|
4.63+3
|
17×
|
分析:(1)化32=4×8,再运用乘法结合律解答,
(2)、(4)运用乘法分配律解答,
(3)运用加法交换律和结合律解答.
(2)、(4)运用乘法分配律解答,
(3)运用加法交换律和结合律解答.
解答:解:(1)2.5×32×12.5,
=(2.5×4)×(8×12.5),
=10×100,
=1000;
(2)8×5×(
-
),
=40×
-40×
,
=16-5,
=11;
(3)4.63+3
+5.37+7
,
=(4.63+5.37)+(3
+7
),
=10+11,
=21;
(4)17×
-
,
=(17-1)×
,
=16×
,
=10.
=(2.5×4)×(8×12.5),
=10×100,
=1000;
(2)8×5×(
| 2 |
| 5 |
| 1 |
| 8 |
=40×
| 2 |
| 5 |
| 1 |
| 8 |
=16-5,
=11;
(3)4.63+3
| 4 |
| 5 |
| 1 |
| 5 |
=(4.63+5.37)+(3
| 4 |
| 5 |
| 1 |
| 5 |
=10+11,
=21;
(4)17×
| 5 |
| 8 |
| 5 |
| 8 |
=(17-1)×
| 5 |
| 8 |
=16×
| 5 |
| 8 |
=10.
点评:本题主要考查学生正确运用简便算法解决问题的能力.
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