题目内容
脱式计算
1
÷0.9×2
27-12×5÷48
2
÷(2.25×
+1
)
[3
-(4
-1
)]×2
.
1
4 |
5 |
1 |
3 |
27-12×5÷48
2
1 |
3 |
1 |
3 |
7 |
8 |
[3
1 |
6 |
1 |
3 |
3 |
4 |
1 |
7 |
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)先算除法,再算乘法.
(2)先算乘法与除法,再算减法.
(3)先算括号中的乘法,再算加法,最后算括号外除法.
(4)先算小括号中的减法,再算中括号中的减法,最后算乘法.
(2)先算乘法与除法,再算减法.
(3)先算括号中的乘法,再算加法,最后算括号外除法.
(4)先算小括号中的减法,再算中括号中的减法,最后算乘法.
解答:
解:(1)1
÷0.9×2
=1.8÷0.9×
=2×
=
;
(2)27-12×5÷48
=27-60÷48
=27-1.25
=25.75;
(3)2
÷(2.25×
+1
)
=2
÷(
×
+1
)
=2
÷(
+1
)
=2
÷
=
;
(4)[3
-(4
-1
)]×2
=[3
-2
]×
=
×
=
4 |
5 |
1 |
3 |
=1.8÷0.9×
7 |
3 |
=2×
7 |
3 |
=
14 |
3 |
(2)27-12×5÷48
=27-60÷48
=27-1.25
=25.75;
(3)2
1 |
3 |
1 |
3 |
7 |
8 |
=2
1 |
3 |
9 |
4 |
1 |
3 |
7 |
8 |
=2
1 |
3 |
3 |
4 |
7 |
8 |
=2
1 |
3 |
21 |
8 |
=
8 |
9 |
(4)[3
1 |
6 |
1 |
3 |
3 |
4 |
1 |
7 |
=[3
1 |
6 |
7 |
12 |
15 |
7 |
=
7 |
12 |
15 |
7 |
=
5 |
4 |
点评:当算式中同时含有分数与小数时,可根据式中数据的特点,将它们化成统一数据形式后,再进行比较.
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