6.36-2.22+2.64-0.78
12.5×(8-0.8)×4
1.25×6.4×0.25×0.2
7.5×10-7.5×6.5+7.5×0.5
(2.6×1.5+1.1)-2.5×8
8÷[(40.75-9.5)×0.4]-0.6.

解:(1)6.36-2.22+2.64-0.78
=(6.36+2.64)-(2.22+0.78)
=9-3
=6;

(2)12.5×(8-0.8)×4
=(12.5×8-12.5×0.8)×4
=(100-10)×4
=90×4
=360;

(3)1.25×6.4×0.25×0.2
=1.25×8×0.8×0.25×0.2
=(1.25×8)×0.8×(0.25×0.2)
=10×0.8×0.05
=10×(0.8×0.05)
=10×0.04
=0.4;

(4)7.5×10-7.5×6.5+7.5×0.5
=7.5×(10-6.5+0.5)
=7.5×4
=30;

(5)(2.6×1.5+1.1)-2.5×8
=(3.9+1.1)-(2.5×4)×2
=5-10×2,
=5-20
=-15;

(6)8÷[(40.75-9.5)×0.4]-0.6
=8÷[31.25×0.4]-0.6
=8÷[(31+0.25)×0.4]-0.6
=8÷[31×0.4+0.25×0.4]-0.6
=8÷[12.4+0.1]-0.6
=8÷12.5-0.6
=0.64-0.6
=0.04.
分析:(1)運(yùn)用加法交換律與結(jié)合律簡算;
(2)運(yùn)用乘法分配律簡算;
(3)把6.4看作8×0.8,運(yùn)用乘法結(jié)合律簡算;
(4)運(yùn)用乘法結(jié)合律簡算;
(5)先算括號(hào)內(nèi)的乘法和括號(hào)外的乘法,再算括號(hào)內(nèi)的加法,最后算括號(hào)外的減法;
(6)先算小括號(hào)內(nèi)的,再算中括號(hào)內(nèi)的,然后算括號(hào)外的除法,最后算括號(hào)外的減法.
點(diǎn)評(píng):解答此題,注意運(yùn)算順序,以及運(yùn)用運(yùn)算定律進(jìn)行簡算.
練習(xí)冊系列答案
相關(guān)習(xí)題

科目:小學(xué)數(shù)學(xué) 來源: 題型:

6.36-2.22+2.64-0.78
12.5×(8-0.8)×4
1.25×6.4×0.25×0.2
7.5×10-7.5×6.5+7.5×0.5
(2.6×1.5+1.1)-2.5×8
8÷[(40.75-9.5)×0.4]-0.6.

查看答案和解析>>

科目:小學(xué)數(shù)學(xué) 來源: 題型:

把下面的算式補(bǔ)充完整.
18.7-16.4+
2.2
2.2

=18.7+
2.2
2.2
-l6.4
=20-16.4
=
3.6
3.6

35.67+
28.65
28.65
+21.35
=35.67+(
28.65
28.65
+21.35)
=35.67+50
=
85.67
85.67

54.37-
0.77
0.77
-9.23
=54.37-(
0.77
0.77
+9.23)
=54.37-10
=
44.37
44.37

33.25+6.23-
3.25
3.25

=33.25-
3.25
3.25
+6.23
=30+6.23
=
36.23
36.23

查看答案和解析>>

科目:小學(xué)數(shù)學(xué) 來源: 題型:閱讀理解

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個(gè)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個(gè)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

查看答案和解析>>

科目:小學(xué)數(shù)學(xué) 來源: 題型:

按規(guī)律填空
(1)2,5,8,
(11)
(11)
,
(14)
(14)

(2)2,7,12,17,22,
(27)
(27)
,
(32)
(32)
;
(3)5,10,15,20,
(25)
(25)
,
(30)
(30)

(4)
(1)
(1)
,
(7)
(7)
,13,19,25,31,37;
(5)1,3,4,7,11,
(18)
(18)
,
(29)
(29)

(6)2,6,18,54,
(162)
(162)
,
(486)
(486)
;
(7)
(1)
(1)
,4,9,16,25,
(36)
(36)
;
(8)1,3,2,4,3,5,
(4)
(4)
,
(6)
(6)
;
(9)4,21,6,18,8,15,10,
(12)
(12)
;
(10)5,20,13,52,3,12,
(15)
(15)
,60.

查看答案和解析>>

同步練習(xí)冊答案