题目内容
简算下面个题
| 32.48-12.5-7.5 | 64×
|
2998×9 |
|
分析:(1)可根据一个数减两个数,等于用这个数减去这两个数的和的减法性质计算;
(2)可将64拆分为63+1后根据乘法分配律计算;
(3)可用凑整法将2998变为3000-2后根据乘法分配律计算;
(4)可将式中的除法算式变为乘法算式后,根据乘法分配律计算.
(2)可将64拆分为63+1后根据乘法分配律计算;
(3)可用凑整法将2998变为3000-2后根据乘法分配律计算;
(4)可将式中的除法算式变为乘法算式后,根据乘法分配律计算.
解答:解:(1)32.48-12.5-7.5
=32.48-(12.5+7.5),
=32.48-20,
=12.48;
(2)64×
=(63+1)×
,
=63×
+
,
=15+
,
=15
.
(3)2998×9
=(3000-2)×9,
=3000×9-2×9,
=27000-18,
=26982;
(4)
×
+
÷
=
×
+
×
,
=(
+
)×
,
=1×
,
=
.
=32.48-(12.5+7.5),
=32.48-20,
=12.48;
(2)64×
| 15 |
| 63 |
=(63+1)×
| 15 |
| 63 |
=63×
| 15 |
| 63 |
| 15 |
| 63 |
=15+
| 15 |
| 63 |
=15
| 15 |
| 63 |
(3)2998×9
=(3000-2)×9,
=3000×9-2×9,
=27000-18,
=26982;
(4)
| 5 |
| 11 |
| 3 |
| 4 |
| 6 |
| 11 |
| 4 |
| 3 |
=
| 5 |
| 11 |
| 3 |
| 4 |
| 6 |
| 11 |
| 3 |
| 4 |
=(
| 5 |
| 11 |
| 6 |
| 11 |
| 3 |
| 4 |
=1×
| 3 |
| 4 |
=
| 3 |
| 4 |
点评:完成本题要注意分析式中数据的特点,然后运用合适的方法计算.
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