题目内容
怎样简便就怎样算
2+1÷(1-
) 1.85×25%+2.15÷4 (
+
)×
-
.
2+1÷(1-
| 3 |
| 4 |
| 8 |
| 9 |
| 2 |
| 3 |
| 3 |
| 4 |
| 2 |
| 3 |
考点:整数、分数、小数、百分数四则混合运算
专题:运算顺序及法则
分析:(1)先算小括号里的减法,再算括号外的除法,最后算加法;
(2)把乘以4化成乘以0.25,再运用乘法的分配律进行简算;
(3)运用乘法的分配律进行简算,再算减法.
(2)把乘以4化成乘以0.25,再运用乘法的分配律进行简算;
(3)运用乘法的分配律进行简算,再算减法.
解答:
解:(1)2+1÷(1-
)
=2+1÷
=2+4
=6;
(2)1.85×25%+2.15÷4
=1.85×25%+2.15×0.25
=(1.85+2.15)×25%
=4×25%
=1;
(3)(
+
)×
-
=
×
+
×
-
=
+
-
=
-
+
=0+
=
.
| 3 |
| 4 |
=2+1÷
| 1 |
| 4 |
=2+4
=6;
(2)1.85×25%+2.15÷4
=1.85×25%+2.15×0.25
=(1.85+2.15)×25%
=4×25%
=1;
(3)(
| 8 |
| 9 |
| 2 |
| 3 |
| 3 |
| 4 |
| 2 |
| 3 |
=
| 8 |
| 9 |
| 3 |
| 4 |
| 2 |
| 3 |
| 3 |
| 4 |
| 2 |
| 3 |
=
| 2 |
| 3 |
| 1 |
| 2 |
| 2 |
| 3 |
=
| 2 |
| 3 |
| 2 |
| 3 |
| 1 |
| 2 |
=0+
| 1 |
| 2 |
=
| 1 |
| 2 |
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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