题目内容

1125-997=998+1246+9989=(8700+870+87)÷87=125×8.8=
1.3+4.25+3.7+3.75=17.15-(3.5-2.85)=3.4×99+3.4=4.8×1.01=
0.4×(2.5÷73)=(1.6+1.6+1.6+1.6)×25    数学公式+数学公式-数学公式)÷数学公式=数学公式=
12.3-2.45-5.7-4.55=数学公式÷2数学公式+数学公式×数学公式=0.125×0.25×64=64.2×87+0.642×1300=
78×36+7.8×741-7数学公式=数学公式×17+数学公式×8=数学公式×数学公式+0.125×数学公式+0.5=2.42÷数学公式+4.58×数学公式-4÷3=
25÷100数学公式=4.25-3数学公式-(2数学公式-1数学公式)=3.8÷3.9+3.9÷0.1+0.1÷3.9=12.1-(数学公式+数学公式)×105=

解:(1)1125-997,
=1125-1000+3,
=125+3,
=128;
(2)998+1246+9989,
=998+(1233+2+11)+9989,
=(998+2)+1233+(11+9989),
=1000+1233+10000,
=12233;
(3)(8700+870+87)÷87,
=8700÷87+870÷87+87÷87,
=100+10+1,
=111;
(4)125×8.8,
=125×8+125×0.8,
=1000+100,
=1100;
(5)1.3+4.25+3.7+3.75,
=(1.3+3.7)+(4.25+3.75),
=5+8,
=13;
(6)17.15-(3.5-2.85)
=17.15+2.85-3.5,
=20-3.5,
=16.5;
(7)3.4×99+3.4,
=3.4×(99+1),
=3.4×100,
=340;
(8)4.8×1.01,
=4.8×1+4.8×0.01,
=4.8+0.048,
=4.848;
(9)0.4×(2.5÷73),
=0.4×2.5÷73,
=1÷73,
=
(10)(1.6+1.6+1.6+1.6)×25,
=1.6×(4×25 ),
=1.6×100,
=160;
(11)(+-)÷
=×36+×36-×36,
=16+30-14,
=32;
(12)
=×100+×
=28+
=
(13)12.3-2.45-5.7-4.55,
=(12.3-5.7)-(2.45+4.55),
=6.6-7,
=-0.4;
(14)÷2+×
=×+×
=(+)×
=1×
=
(15)0.125×0.25×64,
=(0.125×8)×(0.25×8),
=1×2,
=2;
(16)64.2×87+0.642×1300,
=64.2×(87+13),
=64.2×100,
=6420;
(17)78×36+7.8×741-7
=7.8×(360+741-1),
=7.8×1100,
=8580;
(18)×17+×8,
=×17+×17,
=(+)×17,
=×17,
=×17,
=
(19)×+0.125×+0.5,
=(0.875+0.125+1)×0.5,
=(1+1)×0.5,
=2×0.5,
=1;
(20)2.42÷+4.58×-4÷3,
=(2.42+4.58-1)×
=6×
=8;
(21)25÷100
=25÷
=25×
=
(22)4.25-3-(2-1),
=(4.25+1.75)-(+),
=6-6,
=0;
(23)3.8÷3.9+3.9÷0.1+0.1÷3.9,
=(3.8+0.1)÷3.9+3.9÷0.1,
=3.9÷3.9+39,
=1+39,
=40;
(24)12.1-(+)×105,
=12.1-(×105+×105),
=12.1-(7+5),
=12.1-12,
=0.1.
分析:根据小数、分数、整数四则混合运算的顺序进行计算解答.
点评:本题主要考查小数、分数、整数四则混合运算,注意运用运算定律进行简算.
练习册系列答案
相关题目
1.
(1)438+203 (2)256+199 (3)416-302 (4)325-198
(5)278+498 (6)3.6+2.7+6.4+7.3 (7)
4
9
+
5
6
+
5
9
+2
1
6
(8)1.3+4.25+3.7+3
(9)1874-324-476 (10)5-1.4-1.6 (11)30-8.12-4.13-7.75 (12)
7
8
-
4
5
+
1
8
(13)4.3-2.45+5.7-6.55 (14)125×48 (15)25×32 (16)35×1.4
(17)1.25×88 (18)0.25×444 (19)32×0.25×12.5 (20)25×80×0.04×125
(21)1.9×4×0.5 (22)25×1.25×4×0.8 (23)(1.6+1.6+1.6+1.6)×2.5 (24)(0.7+0.7…+0.7)×12.5(80个0.7相加)
(24)9.9×8.6+8.6 (25)99×5.4
(26)4.8×1.01 (27)95×101-95 (28)95×102-190 (29)95.6×18+0.4×18
(30)(
1
3
-
1
6
+
1
4
)×12
(31)(
1
3
+
1
8
-
1
24
)÷
1
24
(32)24×(
1
3
+
1
8
-
1
24
(33)24÷(
1
3
+
1
8
-
1
24
(34)1.25×3.6+1.25×3
2
5
+1
1
4
(35)3.3×
3
4
+0.75×5
7
10
+75%
(36)2
1
2
×6.6+7.5×6
3
5
(37)9.56×180-95.6×8
(38)4.8×37+47×6.3 (39)9.5×8.8+0.12×95 (40)
19
20
×21
(41)
7
30
×33
(42)
2
45
÷
1
46
(43)
2
45
÷
1
48
(44)
2
45
÷42
(45)6×0.75+5×
3
4
-3÷4
(46)5.4÷1.2÷5 (47)270÷18 (48)120÷(1.2×4) (49)73÷0.8÷12.5
(50)16÷2.5 (51)48÷1.25 (52)
3
7
-(
1
2
-
3
7
)+
1
2
(53)84-(54-16)
(54)84-(54+16) (55)9999×7778+3333×6666 (56)3.6×31.4+43.9×6.4 (57)(
3
4
+
5
6
)×
12
5
(58)
7
9
×
13
14
+
2
9
÷
14
13
(59)
23
20
-
1
3
-
2
3
(60)
6
11
×
7
8
-
6
8
×
5
11
(61)
1
2
×
1
4
÷
1
2
×
1
4
(62)
25
17
-
1
3
×
9
8
-
5
8
(63)
8
9
×[
3
7
÷(
2
3
+
1
7
)]
(64)(0.9+5)×3+2.3 (65)56×
1
57
(66)
3
4
+
1
4
÷
3
4
+
1
4
(67)(
3
4
+
1
4
)÷(
3
4
+
1
4
(68)
7
15
÷(
7
30
-
1
15
(69)(
7
30
-
1
15
)÷
7
15
(70)7.2÷(5-0.75-0.25) (71)6.4+3.6÷0.5+4.5 (72)(6.4+3.6)÷0.5+4.5 (73)495÷55+495÷45
(74)8÷0.4+8÷1.6 (75)0.9+99×0.9 (76)5.28-(1.62+2.28) (77)
5
9
-
5
9
+
4
9
(78)4×(
3
8
+)
(79)
5
9
+
3
11
++
(80)2-(
1
2
+
1
25
)-
23
50
(81)
7
18
×
1
4
+
3
4
×
7
18
(82)
7
10
×
11
14
+
11
14
×
3
10
(83)
7
8
×9+
7
8
(84)(5+
5
16
)×
4
5
(85)(
1
6
+
1
8
)×24
(86)(20+
4
7
)×
7
10
(87)
1
13
×39×
8
21
(88)
7
3
×(
3
7
+
3
28
(89)(
1
4
-
1
6
)×12
(90)
40
13
×(26×
3
40
(91)
1
7
+
7
9
+
6
7
+
2
9
(92)17×
3
8
-
3
8
(93)(
8
5
+
8
3
)×
5
8
(94)(
13
24
+
13
16
)÷
13
16
(95)(
3
8
+
3
11
)÷3
(96)(
1
27
-
1
36
)÷
1
9
(97)
3
7
÷
7
11
+
4
7
÷
7
11
(98)
4
5
×(10+
5
6
(99)(21+
7
15
)÷
7
5
(100)
7
13
×
3
4
6
13
(101)
5
2
÷
4
17
+
3
2
÷
4
17
(102)(
5
18
-
5
24
)÷
5
6
(103)
2
3
×
7
3
+
4
5
+
(104)
25
17
_
1
3
×
9
8
-
5
8
(105)
12
7
-(
1
3
÷
7
15
+
4
13
(106)
5
7
+
9
8
×
5
9
+
3
8
(107)1-
5
8
÷
25
28
-
3
10
(108)
1
4
×
3
7
+÷4
(109)5-(4+
6
13
(110)1125-997 (111)7.46-0.83-2.17 (112)12.85-1.17-8.83+1.15 (113)4.5×102
(114)0.4×6.3×25 (115)(4.9+4.9+…+4.9)×2.5(16个4.9相加) (116)7.5×199 (117)(
1
9
+
1
12
)×36
(118)1.2×5.7-1.2+5.3×1.2 (119)0.825×102-82.5 (120)46×
2
45
(121)560÷16÷5
(122)3÷2.5 (123)84+(54-16) (124)
3
11
+
5
12
+
8
11
+
7
12
(125)
12
7
-(
1
3
÷
7
15
+
4
13
(126)3×(
1
12
+
2
15
)+
3
4
(127)7.2÷(5-0.75+0.25) (128)725÷25+275÷25 (129)
1
2
×
1
4
×
2
3
(130)
7
16
×45-
7
16
÷
1
45
(131)48×(
5
6
-
3
8
(132)
12
13
×
4
5
+
1
3
×
1
2
(133)(32+
4
7
)÷4
(134)
1
3
÷
3
8
÷
8
9
(135)46×
2
45
(136)
3
4
×
1
9
+
1
4
÷9

违法和不良信息举报电话:027-86699610 举报邮箱:58377363@163.com

精英家教网