题目内容
(2011?宁南县模拟)脱式计算,能简算的要简算.
15.8-
|
3
|
6.6-1
|
197×
|
分析:(1)根据加法的结合律及连续减去两个数等于减去两个数的和简算;
(2)先算乘、除法,再算加法;
(3)把百分数化为分数,再根据四则运算的方法计算;
(4)注意此题不能够先算
+
,要先算乘法,再算加法.
(2)先算乘、除法,再算加法;
(3)把百分数化为分数,再根据四则运算的方法计算;
(4)注意此题不能够先算
| 97 |
| 98 |
| 1 |
| 98 |
解答:解:(1)15.8-
+14.2-
,
=15.8+14.2-(
+
),
=30-1,
=29;
(2)3
÷
+
×1
,
=
×
+
×
,
=
+
,
=
;
(3)6.6-1
+(87.5%÷
+
×0.8),
=6.6-1.6+(
×
+0.1),
=5+0.8,
=5.8;
(4)197×
+
.
=
+
,
=
,
=195.
| 7 |
| 18 |
| 11 |
| 18 |
=15.8+14.2-(
| 7 |
| 18 |
| 11 |
| 18 |
=30-1,
=29;
(2)3
| 2 |
| 3 |
| 5 |
| 8 |
| 3 |
| 5 |
| 1 |
| 3 |
=
| 11 |
| 3 |
| 8 |
| 5 |
| 3 |
| 5 |
| 4 |
| 3 |
=
| 88 |
| 15 |
| 12 |
| 15 |
=
| 20 |
| 3 |
(3)6.6-1
| 3 |
| 5 |
| 5 |
| 4 |
| 1 |
| 8 |
=6.6-1.6+(
| 7 |
| 8 |
| 4 |
| 5 |
=5+0.8,
=5.8;
(4)197×
| 97 |
| 98 |
| 1 |
| 98 |
=
| 19109 |
| 98 |
| 1 |
| 98 |
=
| 19110 |
| 98 |
=195.
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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