tính nhanh :
a, 35 .34 +35.38+65.75+65.45
b, 39.8+60.2+21.8
c, 36.28+36.82+64.69+64.4
d, 123.1001
Bài 2. Tính bằng cách hợp lí nhất:
a) 38. 63 + 37. 38 b) 12.53 + 53. 172– 53. 84
c) 35.34 +35.38 + 65.75 + 65.45 d) 39.8 + 60.2 + 21.8
e) 36.28 + 36.82 + 64.69 + 64.41
a)38.63+37.38
=38.(63+37)
=38.100
=3800
a) \(=38\left(63+37\right)=38.100=3800\)
b) \(=53\left(12+172-84\right)=53.100=5300\)
c) \(=35\left(34+38\right)+65\left(75+45\right)=35.72+65.120=10422\)
d) \(=39.8+15.8+21.8=8\left(39+15+21\right)=8.75=600\)
e) \(=36\left(28+82\right)+64\left(69+41\right)=36.110+64.110=110\left(36+64\right)=110.100=11000\)
thuc hien phep tinh
a)28.64+14.72
b)3.25.8+4.37.6+2.32.12
c)19.126+37.38
d)35.34+35.38 +65.75+65.45
e)39.8+60.2+21.8
f)36.38+36.82+64.69+64.41
m)37.7+80.3 +43.7
n)43.37+93.43+57.61+69.57
a 2008
b 2256
c 3800
d 10320
e 600
f 11360
m 800
n 13000
a)2800
b)2256
c)3800
d)10320
e)600
f)11360
m)800
n)13000
Bài 2. Tính bằng cách hợp lí nhất:
a) 38. 63 + 37. 38
b) 12.53 + 53. 172– 53. 84
c) 35.34 +35.38 + 65.75 + 65.45
d) 39.8 + 60.2 + 21.8
e) 36.28 + 36.82 + 64.69 + 64.41
Bài 2:
a)38.63+37.38=38(63+37)=3800
b)12.53+53.172– 53.84=53(12+172-84)=5300
c)35.34+35.38+65.75+65.45=35(34+38)+65(75+45)=2520+7800=10320
d)39.8 +60.2 +21.8=8(39+21)+120=480+120=600
e)36.28+36.82+64.69+64.41=36(28+82)+64(69+41)=3960+7040=11000
Bài 7: Tính nhanh
c) 3. 25. 8 + 4. 37. 6 + 2. 38. 12 d) (1200 + 60) : 12
e) 12.53 + 53. 172 – 53. 84 g) (2100 – 42) : 21
h) 39.8 + 60.2 + 21.8 i) 36.28 + 36.82 + 64.69 + 64.41
c) 3. 25. 8 + 4. 37. 6 + 2. 38. 12
= 24. 25 + 24 . 37 + 24.38
= 24.(25 +37+ 38)
= 24. 100 = 2400
d) (1200 + 60) : 12
= 1200 : 12 + 60: 12
= 100 + 5 = 105
e) 12.53 + 53. 172 – 53. 84
= 53 . ( 12+ 172 - 84)
= 53 . 100 = 5300
g) (2100 – 42) : 21
= 2100 : 21 - 42: 21
= 100 - 2 = 98
h) 39.8 + 60.2 + 21.8
= 39 .8 + 60 . 2 + 21 . 8
= 8.( 39 + 21) + 120
= 8 . 60 + 120 = 480 + 120 = 600
i) 36.28 + 36.82 + 64.69 + 64.41
= 36.(28 + 82) + 64.( 69 + 41) = 36. 110 + 64 . 110 = 110.( 36 + 64) =110. 100 = 11000
Nhớ tick nha em chị làm mãi mới được đấy
tinh nhanh:
a) 35.34+ 35.38+65.75+65.45
b) 12.53+53.172-53.84
c) 36.28+36.82+64.69+64.41
d)4.7.16.25
đ)3.25.8+4.37.6+2.38.12
e) (1999+313)-1999
f) 2023 - (34 + 1560)
Dấu chấm là dấu nhân.
a ) mik lười nên ko làm .....
b ) Bạn vận dụng tính chất
c ) ....Tương tự a và b
d ) 4.7.16.25
= ( 4.25 ) . ( 7.16 )
= 100 . 112
= 11200
đ )
= ( 3.8 ) . 25 + ( 4.6 ) . 37 + ( 2.12 ) . 38
= 24.25 + 24.37 + 24.38
= 24. ( 25 + 37 + 38 )
= 24. 100
=24 00
e ) f) bạn vận dụng đi
BÀI NHIỀU QUÁ ! MIK LM ĐC TỪNG ẤY VÀ GỢI Ý CHO BẠN > MIK NHÉ , MẤT CÔNG LẮM ĐẤY !
a)35.34+35.38+65.75+65.45
= 35(34+38)+65(75+45)
= 35.72+65.120
= 2520 + 7800
= 10320
b)12.53+53.172-53.84
= 53(12+172-84)
= 53.100
= 5300
c)36.28+36.82+64.69+64.41
= 36(28+82)+64(69+41)
= 36.110+64.110
= 110(36+64)
= 110.100
= 11000
d)4.7.16.25
= (4.25).7.16
= 100.7.16
= 11200
đ)3.25.8+4.37.6+2.38.12
= (3.8).25+(4.6).37+(2.12).38
= 24.25+24.37+24.38
= 24(25+37+38)
= 24.100
= 2400
e)(1999+313)-1999
= 1999+313-1999
= 313+1999-1999
= 313
f)2023-(34+1560)
= 2023-34-1560
= 429
Bài 7: Tính nhanh
c) 3. 25. 8 + 4. 37. 6 + 2. 38. 12 d) (1200 + 60) : 12
e) 12.53 + 53. 172 – 53. 84 g) (2100 – 42) : 21
h) 39.8 + 60.2 + 21.8 i) 36.28 + 36.82 + 64.69 + 64.41
k) 32. 47 + 32. 53 l) 37.7 + 80.3 +43.7
m) 113.38 + 113.62 + 87.62 + 87.38 n) 123.456 + 456.321 –256.444
p) 43.37 + 93.43 + 57.61 + 69.57 q) 38. 63 + 37. 38
r) 35.34 +35.38 + 65.75 + 65.45
c, 3.25.8 + 4.37.6 + 2.38.12
= (3.8).25 + (4.6).37 + (2.12).38
= 24.25 + 24.37 + 24.38
= 24.(25 + 37 + 38)
= 24.100
= 2400
d, (1200 + 60):12
= 1200: 12 + 60: 12
= 100 + 5
= 105
e, 12.53 + 53.172 - 53.84
= 53.(12 + 172 - 84)
= 153.( 184 - 84)
= 153. 100
= 15300
Bài 7: Tính nhanh
a) 37. 38 + 62. 37 b) 28. 64 + 28. 36
c) 3. 25. 8 + 4. 37. 6 + 2. 38. 12 d) (1200 + 60) : 12
e) 12.53 + 53. 172 – 53. 84 g) (2100 – 42) : 21
h) 39.8 + 60.2 + 21.8 i) 36.28 + 36.82 + 64.69 + 64.41
k) 32. 47 + 32. 53 l) 37.7 + 80.3 +43.7
m) 113.38 + 113.62 + 87.62 + 87.38 n) 123.456 + 456.321 –256
a. 37. 38 + 62. 37
= 37 . (38 + 62)
= 37 . 100
= 3700
b. 28. 64 + 28. 36
= 28 . (64 + 36)
= 28 . 100
= 2800
c. 3. 25. 8 + 4. 37. 6 + 2. 38. 12
= 3 . 8 . 25 + 4 . 6 . 37 + 12 . 2 . 38
= 24 . 25 + 24 . 37 + 24 . 38
= 24 . (25 + 37 + 38)
= 24 . 100
= 2400
314.67+341.67 +659.83
42.53+47.156-47.114
35.34+35.38.65.75.65.45
39.8+60.2+21+8
36.28=36.82=64.69+64.4
87.23+13.93+70.87
126.23=136.17-40.36
29.87-64.71-23.29 help me
ai giúp với điiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii mà
a)42.53+47.156-47.114
b)35.13+35.17+65.75-65.45
c)53.39+47.39-53.21-47.21
d)36.28+36.82+64.69+64.41
e)78.31+78.24+78.17+22.72
\(a,\)\(42.53+47.156-47.114\)
\(42.53+47\left(156-114\right)\)
\(=42.53+47.42\)
\(=42\left(53+47\right)\)
\(=42.100\)
\(=4200\)
\(b,\)\(35.13+35.17+65.75-65.45\)
\(=35\left(13+17\right)+65\left(75-45\right)\)
\(=35.30+65.30\)
\(=30\left(35+65\right)\)
\(=30.100\)
\(=3000\)
a)42.53+47.156-47.114
= 42.53+47(156-114)
=42.53+47.42
=42(53+47)=42.100=4200
b)35.13+35.17+65.75-65.45
=35(13+17)+65(75-45)
=35.30+65.30
=30(35+65)
=30.100=3000