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

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) \(=36\left(28+82\right)+64\left(69+41\right)=36.110+64.110=110\left(36+64\right)=110.100=11000\)

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

ghi sai toán olớp 6 nhé ai giúp mình với

b: \(=53\left(12+172-84\right)=5300\)

d: \(=1000\cdot82=82000\)

a) \(146.53+146.48-146\)

\(=146\left(53+48-1\right)\)

\(=146.100\)

\(=14600\)

b) \(13.27+18.\left(-27\right)+105.27\)

\(=13.27+\left(-18\right).27+105.27\)

\(=27\left[13+\left(-18\right)+105\right]\)

\(=27.100\)

\(=2700\)

c) \(-124-\left(-564-24\right)-364\)

\(=-124-564+24-364\)

\(=-124+\left(-564\right)+24+\left(-364\right)\)

\(=\left[\left(-124\right)+24\right]+\left[\left(-564\right)+\left(-364\right)\right]\)

\(=\left(-100\right)+\left(-200\right)=-300\)

d) \(\left(1324+987-456\right)-\left(324-13\right)+556\)

\(=1324+987-456-324+13+556\)

\(=1324+987+\left(-456\right)+\left(-324\right)+13+556\)

\(=\left[1324+\left(-324\right)\right]+\left[987+13\right]+\left[\left(-456\right)+556\right]\)

\(=1000+1000+100=2100\)

e) \(2-4+6-8+...........-2008+2010\) (860 số hạng)

\(=\left(2-4+6-8\right)+\left(10-12+14-16\right)+...........+\left(2002-2004+2006-2008\right)\)(215 nhóm)

\(=0+0+......+0=0\)

f) \(36.28+36.82+64.69+64.41\)

\(=36\left(28+82\right)+64\left(69+41\right)\)

\(=36.110+64.110\)

\(=110\left(36+64\right)\)

\(=110.100=11000\)

g) \(35.34+35.86+65.75+65.45\)

\(=35\left(34+86\right)+65\left(75+45\right)\)

\(=35.1200+65.1200\)

\(=1200\left(35+65\right)\)

\(=1200.100=120000\)

sao nhìu v........

a) 23.56 + 56.77 = (23 + 77).56 = 100.56 = 5600.

b) 32.19 + 32 = 32.(19 +1) = 32.20 = 640.

c) 35.34 + 35.86 + 65.75 + 65.45 = 35.(34 + 86) + 65.(75 + 45)

= 120.35+120.65 -120.(35 + 65) = 12000.

d) 43.17 + 29.57 +13.43 + 57 = 43.(17 +13) + 57.(29 +1)

= 43.30 + 57.30 = 30. (43+57) = 3000.

e) 3.25.8 + 4.37.6 + 2.3812 - 24.25 + 24.37 + 24.38

= 24.(25 + 37 + 38) = 2400.

f) 64.16 + 81.84+17.16 = 16.(64+17)+81.84 = 16.81+81.84

= 81.(16 + 84) = 8100

a) 23.56 + 56.77 = (23 + 77).56 = 100.56 = 5600.

b) 32.19 + 32 = 32.(19 +1) = 32.20 = 640.

c) 35.34 + 35.86 + 65.75 + 65.45 = 35.(34 + 86) + 65.(75 + 45)

= 120.35+120.65 -120.(35 + 65) = 12000.

d) 43.17 + 29.57 +13.43 + 57 = 43.(17 +13) + 57.(29 +1)

= 43.30 + 57.30 = 30. (43+57) = 3000.

e) 3.25.8 + 4.37.6 + 2.3812 - 24.25 + 24.37 + 24.38

= 24.(25 + 37 + 38) = 2400.

f) 64.16 + 81.84+17.16 = 16.(64+17)+81.84 = 16.81+81.84

= 81.(16 + 84) = 8100