题目内容
(2012?翠屏区模拟)
计算下面各题. 789+10570÷35 |
5.92-5.2÷0.8×0.6 | (2.5-0.125)×0.8+1.24 | ||||||||||||||||||
[1-(
|
4-
|
1-(
|
分析:(1)先算除法,再算加法;
(2)先算除法,再算乘法,最后算减法;
(3)先运用乘法分配律简算,再算加法;
(4)先算小括号里面的减法,再算中括号里面的减法,最后算括号外的除法;
(5)先算除法,再从左到右计算;
(6)先算小括号里面的除法,再算小括号里面的减法,然后算括号外的除法,最后算括号外的减法.
(2)先算除法,再算乘法,最后算减法;
(3)先运用乘法分配律简算,再算加法;
(4)先算小括号里面的减法,再算中括号里面的减法,最后算括号外的除法;
(5)先算除法,再从左到右计算;
(6)先算小括号里面的除法,再算小括号里面的减法,然后算括号外的除法,最后算括号外的减法.
解答:解:(1)789+10570÷35,
=789+302,
=1091;
(2)5.92-5.2÷0.8×0.6,
=5.92-6.5×0.6,
=5.92-3.9,
=2.02;
(3)(2.5-0.125)×0.8+1.24,
=2.5×0.8-0.125×0.8+1.24,
=2-0.1+1.24,
=1.9+1.24,
=3.14;
(4)[1-(
-
)]÷
,
=[1-
]÷
,
=
×
,
=
;
(5)4-
÷4-
,
=4-
-
,
=3
-
,
=3
;
(6)1-(
-
÷
)÷
,
=1-(
-
)÷
,
=1-
÷
,
=1-
,
=
.
=789+302,
=1091;
(2)5.92-5.2÷0.8×0.6,
=5.92-6.5×0.6,
=5.92-3.9,
=2.02;
(3)(2.5-0.125)×0.8+1.24,
=2.5×0.8-0.125×0.8+1.24,
=2-0.1+1.24,
=1.9+1.24,
=3.14;
(4)[1-(
3 |
4 |
3 |
8 |
5 |
12 |
=[1-
3 |
8 |
5 |
12 |
=
5 |
8 |
12 |
5 |
=
3 |
2 |
(5)4-
4 |
7 |
4 |
7 |
=4-
1 |
7 |
4 |
7 |
=3
6 |
7 |
4 |
7 |
=3
2 |
7 |
(6)1-(
3 |
4 |
3 |
4 |
6 |
5 |
7 |
4 |
=1-(
3 |
4 |
5 |
8 |
7 |
4 |
=1-
1 |
8 |
7 |
4 |
=1-
1 |
14 |
=
13 |
14 |
点评:四则混合运算的顺序:
1、如果是同一级运算,一般按从左往右依次进行计算;
2、如果既有加减、又有乘除法,先算乘除法、再算加减;
3、如果有括号,先算括号里面的;
4、如果符合运算定律,可以利用运算定律进行简算.
1、如果是同一级运算,一般按从左往右依次进行计算;
2、如果既有加减、又有乘除法,先算乘除法、再算加减;
3、如果有括号,先算括号里面的;
4、如果符合运算定律,可以利用运算定律进行简算.
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