题目内容

14.76-5.76-
8
9
4
4
9
÷8
8
11
×2
2
11
64
1
17
×
1
9
6
12
13
×5-3
25
26
×2
13×
5
12
+4
3
5
×10
198÷198
198
199
+
1
200
12.5×
1
8
+3
3
4
×1.25
2
3
+
2
15
+
2
35
+
2
63
(3.7×5
7
10
-4.7×3.7)÷
1
3
[0.3+(
1
2
+□)×3]÷0.3=860
56×
54
55
18.75-(4.5-7.25)
3.6×31
2
5
+3.14×64
132
1
130
÷131
2
13
+4×
3
7
+5×
4
13
+6×
5
7
112×(24-4
4
5
)÷2.4
(81.4+
1
6
+
1
4
+
1
5
)÷(
1
4
+
1
5
+
1
6
41.2×8.1+11×9
1
4
+53.7×1.9
1
2
+
1
6
+
1
12
+
1
20
+
1
30
+
1
42
+
1
56
1
1×4
+
1
4×7
+
1
7×10
+…+
1
97×100
分析:(1)按照从左向右的顺序进行计算;
(2)按照从左向右的顺序进行计算;
(3)把带分数化成假分数,再约分计算;
(4)根据乘法分配律进行计算;
(5)先算乘法,再算减法;
(6)先算乘法,再算加法;
(7)根据乘法分配律进行计算;
(8)根据分数的拆项进行计算;
(9)小括号里面的根据乘法分配律进行计算,再算除法;
(10)把□看作未知数,根据等式的性质进行解方程即可;
(11)根据乘法分配律进行计算;
(12)去掉括号,再根据加法交换律进行计算;
(13)根据乘法分配律进行计算;
(14)根据乘法分配律进行计算;
(15)根据加法交换律和结合律进行计算;
(16)根据乘法分配律进行计算;
(17)先算小括号里面的加法,根据乘法分配律进行计算;
(18)根据乘法分配律进行计算;
(19)根据分数的拆项进行计算;
(20)根据分数的拆项进行计算.
解答:解:
(1)14.76-5.76-
8
9

=9-
8
9

=8
1
9


(2)4
4
9
÷8
8
11
×2
2
11

=
40
9
×
11
96
×
24
11

=
10
9


(3)64
1
17
×
1
9

=
1089
17
×
1
9

=
121
17


(4)6
12
13
×5-3
25
26
×2,
=(6+
12
13
)×5-(3+
25
26
)×2,
=(6×5+
12
13
×5)-(3×2+
25
26
×2),
=30+
60
13
-6-
25
13

=(30-6)+(
60
13
-
25
13
),
=24+
35
13

=26
9
13


(5)13×
5
12
+4
3
5
×10,
=5
5
12
+46,
=51
5
12


(6)198÷198
198
199
+
1
200

=198×
199
198×199+198
+
1
200

=
199
200
+
1
200

=1;

(7)12.5×
1
8
+3
3
4
×1.25,
=1.25×10×
1
8
+3
3
4
×1.25,
=1.25×
5
4
+3
3
4
×1.25,
=1.25×(
5
4
+3
3
4
),
=1.25×5,
=6.25;

(8)
2
3
+
2
15
+
2
35
+
2
63

=
2
1×3
+
2
3×5
+
2
5×7
+
2
7×9

=1-
1
3
+
1
3
-
1
5
+
1
5
-
1
7
+
1
7
-
1
9

=1-
1
9

=
8
9


(9)(3.7×5
7
10
-4.7×3.7)÷
1
3

=3.7×(5
7
10
-4.7)÷
1
3

=3.7×1÷
1
3

=3.7÷
1
3

=11.1;

(10)[0.3+(
1
2
+□)×3]÷0.3=860,
[0.3+(
1
2
+□)×3]÷0.3=860,
[0.3+1.5+□×3]÷0.3=860,
[1.8+□×3]÷0.3=860,
6+10×□=860,
10×□=854,
□=85.4;

(11)56×
54
55

=(55+1)×
54
55

=55×
54
55
+1×
54
55

=54+
54
55

=54
54
55


(12)18.75-(4.5-7.25),
=18.75-4.5+7.25,
=(18.75+7.25)-4.5,
=26-4.5,
=21.5;

(13)3.6×31
2
5
+3.14×64,
=3.6×31.4+3.14×64,
=3.6×31.4+31.4×6.4,
=(3.6+6.4)×31.4,
=10×31.4,
=314;

(14)132
1
130
÷131,
=(131+1
1
130
)×
1
131

=131×
1
131
+1
1
130
×
1
131

=1+
131
130
×
1
131

=1+
1
130

=1
1
130


(15)3×
2
13
+4×
3
7
+5×
4
13
+6×
5
7

=(3×
2
13
+5×
4
13
)+(4×
3
7
+6×
5
7
),
=
26
13
+
42
7

=2+6,
=8;

(16)112×(24-4
4
5
)÷2.4,
=112×(24-4.8)×
5
12

=112×(24×
5
12
-4.8×
5
12
),
=112×(10-2),
=112×8,
=896;

(17)(81.4+
1
6
+
1
4
+
1
5
)÷(
1
4
+
1
5
+
1
6
),
=(81.4+
37
60
)÷
37
60

=(81.4+
37
60
)×
60
37

=81.4×
60
37
+
37
60
×
60
37

=132+1,
=133;

(18)41.2×8.1+11×9
1
4
+53.7×1.9,
=41.2×8.1+11×9.25+(41.2+12.5)×1.9,
=41.2×8.1+11×9.25+41.2×1.9+12.5×1.9,
=(41.2×8.1+41.2×1.9)+11×9.25+12.5×1.9,
=41.2×(8.1+1.9)+11×(8+1.25)+12.5×1.9,
=41.2×10+11×8+11×1.25+1.25×19;
=412+88+1.25×(11+19),
=500+1.25×30,
=500+37.5,
=537.5;

(19)
1
2
+
1
6
+
1
12
+
1
20
+
1
30
+
1
42
+
1
56

=
1
1×2
+
1
2×3
+
1
3×4
+
1
4×5
+
1
5×6
+
1
6×7
+
1
7×8

=1-
1
2
+
1
2
-
1
3
+
1
3
-
1
4
+
1
4
-
1
5
+
1
5
-
1
6
+
1
6
-
1
7
+
1
7
-
1
8

=1-
1
8

=
7
8


(20)
1
1×4
+
1
4×7
+
1
7×10
+…+
1
97×100

=
1
3
×(1-
1
4
+
1
4
-
1
7
+
1
7
-
1
10
+…+
1
97
-
1
100
),
=
1
3
×(1-
1
100
),
=
1
3
×
99
100

=
33
100
点评:四则运算,先弄清运算顺序,然后再进一步计算,能简算的要简算.
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