Đáp số:

a) 79 608

b) 145 375

c) 665 412

\(36\cdot532+64\cdot532=532\cdot100=53200\)

36 x 532 + 64 x 532

=(36+64)x532

= 100x532

=53 200

245 x 327 - 245 x 26 - 245

=245x327-245x26-245x1

=245x(327-26-1)

=245x300

=73 500

 a)12 x 11 + 21 x 11 x 11 + 11 x 33

= ( 12 x 11 ) + ( 21 x 11 x 11 ) + ( 11 x 33 )

= 

= 

b)132x11-11x32-54x11

= ( 132 x 11 ) - ( 11 x 32 ) - ( 54 x 11 )

= 

\(a,=11\times\left(12+21+33\right)=11\times66=726\\ b,=11\times\left(132-32-54\right)=11\times46=506\\ c,=11\times\left(245+365\right)=11\times610=6710\\ d,=75\times\left(78+89+123\right)=75\times290=21750\\ e,=\left(2\times50\right)\times\left(250\times8\right)=100\times2000=200000\\ g,=1994\times\left(867+11\right)=1994\times878=1750732\)

a) 12 x 11 + 21 x 11 + 11 x 33

= 11 x ( 12 + 21 + 33)

= 11 x 66

= 726

b) 132 x 11 - 11 x 32 - 54 x 11

= 11 x ( 132 - 32 - 54)

= 11 x 46

= 506

c) 245 x 11 + 11 x 365

= 11 x ( 245 + 365 )

= 11 x 610 = 6710

d) 78 x 75 + 75 x 89 + 75 x 123

= 75 x ( 78 + 89 + 123)

= 75 x 290 = 21750

e) 2 x 250 x 50 x 8

= (2 x 50) x ( 250 x 8)

= 100 x 2000 = 200000

g) 1994 x 867 + 1994 x 11

= 1994 x ( 867 + 11)

= 1994 x 878 = 1750732

a) 125.3+125.125.6

=125.3+125.750

=125.(3+750)

=125.753

=94125

b) (245.99+245)-(145.101-145)

=(245.(99+1))-(145.(101-1))

=245.100-145.100

=(245-145).100

=100.100

=10000

c) 154.(28+52)-45.(26+54)

=154.80-45.80

=(154-45).80

=109.80

=8720

a) 125x3+125+125x6

=125x(3+1+6)

=125x10

=1250

b) (245x99+245)-(145x101-145)

=(245x99+245)-(145x100)

=(245x100)-14500

=24500-14500

10000

c) 154x80-45x80

=80x(145-45)

=80x100

=8000

a, 125 x 3 + 125 x 125 x 6

=125 x 3 + 125 x 750

=125 x( 3+750)

=125 x753

=94125

b, ( 245 x 99 + 245 ) - ( 145 x 101 - 145 )

=[245 x ( 99+1 )] - [145 x ( 101-1 )]

=( 245 x 100 ) - ( 145 x 100 )

=24500 - 14500

=10 000

c, 154 x ( 28 + 52 ) - 45 x ( 26 + 54 )

=154 x 80 - 45 x 80

=(154-45)x80

=109 x80

=8720

a) 36 x 532 + 63 x 532 + 532

= 532 x (36 + 63 + 1)

= 532 x 100

= 53200

b) 679 + 679 x 123 - 679 x 24

= 679 x (1 + 123 - 124)

= 679 x 0

= 0

c) 245 x 327 - 245 x 18 - 9 x 245

= 245 x (327 - 18 - 9)

= 245 x 300

= 73500

a)

\(36\times532+63\times532+532\)

\(=36\times532+63\times532+532\times1\)

\(=532\times\left(36+63+1\right)\)

\(=532\times100\)

\(=53200\)

b)

\(679+679\times123-679\times24\)

\(=679\times1+679\times123-679\times24\)

\(=679\times\left(1+123-24\right)\)

\(=679\times100\)

\(=67900\)

c)

\(245\times327-245\times18-9\times245\)

\(=245\times\left(327-18-9\right)\)

\(=245\times300\)

\(=73500\)

a)

   36 x 532 + 63 x 532 + 532

= 36 x 532 + 63 x 532 + 532 x 1

= ( 36 + 63 + 1 ) x 532

=              100 x 532

=                 53200

b)

   679 + 679 x 123 - 679 x 24

= 679 x 1 + 679 x 123 - 679 x 24

= 679 x ( 1 + 123 - 24 )

=  679 x 100

=    67900

c)

  245 x 327 - 245 x 18 - 9 x 245 

= 245 x ( 327 - 18 - 9 )

=  245 x 300

=        73500 

a 79608, 145375, 665412

b, 125.125=15625

TL :

a) 248 × 321 = 79 608

   1163 × 125 = 145 375

   3124 × 213 =  665 412

b) Diện tích của mảnh vườn là :

     125 × 125 = 15 625 (m²)

_HT_

a) 248 x 321 = 79 608                                   1163 x 125 = 145 375                 3124 x 213 = 665 412

b) diện tích mảnh vườn đó là 125 x 125 = 15625 ( m² )

các bạn nhớ k nhé

Bài 2: Tính bằng cách thuận tiện nhất

\(\text{a. 1255 + 436 + 145}\)

\(=\left(1255+145\right)+436\)

\(=1400+436\)

\(=1836\)

\(\text{b. 142 x 12 + 142 x 18}\)

\(=142\times\left(12+18\right)\)

\(=142\times30\)

\(=4260\)

\(\text{c. 4 x 18 x 25}\)

\(=\left(25\times4\right)\times18\)

\(=100\times18\)

\(=1800\)

Bài 2:

a: \(=1400+436=1836\)

b: =142(12+18)

=142*30

=4260

c: \(=100\cdot18=1800\)

Bài 3:

a: \(41m^219dm^2>409dm^2\)

b: \(90000cm^2< 90m^2\)

c: \(30m^26dm^2< 3060dm^2\)

d: \(8012cm^2>8dm^212cm^2\)

e: \(5dm^29cm^2=509cm^2\)

f: \(3940dm^2=39m^240dm^2\)

g: \(300m^26dm^2>3006dm^2\)

h: \(2009cm^2< 21dm^2\)