题目内容
(2011?靖江市)
| 48×31+31×51+31 |
| ||||||
|
99×25. |
分析:①④运用乘法的分配律计算解答.②算式首先把除以3改写成乘以
即可运用乘法分配律.③按照同级运算从左向右依次计算.
| 1 |
| 3 |
解答:解:①48×31+31×51+31,
=31×(48+51+1),
=31×100,
=3100;
②
÷3+
×
,
=
×
+
×
,
=
×(
+
),
=
×1,
=
;
③
×1427÷
,
=
×
×
,
=
;
④99×25,
=(100-1)×25,
=2500-25,
=2475.
=31×(48+51+1),
=31×100,
=3100;
②
| 8 |
| 11 |
| 1 |
| 3 |
| 3 |
| 11 |
=
| 8 |
| 11 |
| 1 |
| 3 |
| 1 |
| 3 |
| 3 |
| 11 |
=
| 1 |
| 3 |
| 3 |
| 11 |
| 8 |
| 11 |
=
| 1 |
| 3 |
=
| 1 |
| 3 |
③
| 1 |
| 7 |
| 8 |
| 9 |
=
| 1 |
| 7 |
| 14 |
| 27 |
| 9 |
| 8 |
=
| 1 |
| 12 |
④99×25,
=(100-1)×25,
=2500-25,
=2475.
点评:本题根据数值的特点运用乘法的分配律进行计算即可.考查了学生的计算能力.
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