题目内容
能简算的要简算.
|
198÷
|
186×
| ||||||||||||
8.16-3.875-2.125-1.16 |
|
分析:算式(1)根据四则混合运算的运算顺序计算即可.算式(2)、(3)可据乘法分配律进行计算;(4)一个数减去两个数,可以用这个数减去这两个数的和.(5)一个数减去两个数的和,可以用这个数分别减去这两个数.
解答:解:(1)
×
÷
,
=
×
×
,
=
;
(2)198÷
+202×
,
=198×
+202×
,
=(198+202)×
,
=400×
,
=300;
(3)186×
,
=(185+1)×
,
=185×
+1×
,
=67
;
(4)8.16-3.875-2.125-1.16,
=8.16-1.16-(3.875+2.125),
=7-6,
=1;
(5)
-(
+
),
=
-
-
,
=1-
,
=
;
4 |
9 |
1 |
5 |
4 |
5 |
=
4 |
9 |
1 |
5 |
5 |
4 |
=
1 |
9 |
(2)198÷
4 |
3 |
3 |
4 |
=198×
3 |
4 |
3 |
4 |
=(198+202)×
3 |
4 |
=400×
3 |
4 |
=300;
(3)186×
67 |
185 |
=(185+1)×
67 |
185 |
=185×
67 |
185 |
67 |
185 |
=67
67 |
185 |
(4)8.16-3.875-2.125-1.16,
=8.16-1.16-(3.875+2.125),
=7-6,
=1;
(5)
19 |
17 |
1 |
8 |
2 |
17 |
=
19 |
17 |
2 |
17 |
1 |
8 |
=1-
1 |
8 |
=
7 |
8 |
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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