Tính bằng cách thuận tiện nhất :

a) 3254 + 146 + 1698

= ( 3254 + 146 ) + 1698

= 3400 + 1698 

= 5098

b) 467 + 999 + 9533

= ( 467 + 9533 ) + 999

= 10000 + 999

= 10999

c) 789 + 285 + 15

= 789 + ( 285 + 15 )

= 789 + 300

= 1089

Tính bằng cách thuận tiện nhất:

a)3254+146+1698

= (3254+146)+1698

= 3400+1698

= 5098

b)467+999+9533

= 467+9533+999

= (467+9533)+999

= 10999+999

=11998

c)789+285+15

= 789+(285+15)

= 789+300

=1089

Tính bằng cách thuận tiện nhất :

a) 3254 + 146 + 1698

= ( 3254 + 146 ) + 1698

= 3400 + 1698 

= 5098

b) 467 + 999 + 9533

= ( 467 + 9533 ) + 999

= 10000 + 999

= 10999

c) 789 + 285 + 15

= 789 + ( 285 + 15 )

= 789 + 300

= 1089

677 + 969 + 123 = 677 + 123 + 969 = 1769

9565:296 

=

316x( 96+3+1)

=316x 100

=31600

164x(50x2)

=164x 100

=16400

a. 316 x 96 + 316 x 3 + 316

= 316 x ( 96 + 3 + 1)

= 316 x 100 

= 31600

b. 164 x 50 x 2

= 164 x 100

= 16400

a) 4 x 78 x 5

= (4 x 5) x 78

= 20 x 78

= 1560

b) 2 x 99 x 5

= (2 x 5) x 99

= 10 x 99

= 990

\(7,\)

\(a,=\left(4\times5\right)\times78=20\times78=1560\)

\(b,=\left(2\times5\right)\times99=10\times99=990\)

a. 4 x 78 x 5 = 4 x 5 x 78 = 20 x 78 = 1560

b. 2 x 99 x 5 = 2 x 5 x 99 = 10 x 99 = 990

a: =150x70=10500

b: =999(15+85)=99900

c: =72072:72=1001

a.31500:3=10500

b.(165:11+85)x999

=(15+85)x999

=100x999

=99900

c.(72072:6):12

=12012:12

=1001

d.18180:36=505

a.31500:3=10500

b.(165:11+85)x999

=(15+85)x999

=100x999

=99900

c.(72072:6):12

=12012:12

=1001

d.18180:36=505

96 + 78 + 4 = 96 + 4 + 78 = 100 + 78 = 178

a) 98+3+97+2
= (98+2)+(97+3)
= 100 + 100
= 200

 56+399+1+4
= (56+4)+(399+1)
= 60 + 400
= 460

b)364+136+219+181
= (364+136)+(219+181)
= 500 + 400
= 900

 178+277+123+422
= (178+422)+(277+123)
= 600 + 400
= 1000
 

a) 98+3+97+2
= (98+2)+(97+3)
= 100 + 100
= 200

 56+399+1+4
= (56+4)+(399+1)
= 60 + 400
= 460

b)364+136+219+181
= (364+136)+(219+181)
= 500 + 400
= 900

 178+277+123+422
= (178+422)+(277+123)
= 600 + 400
= 1000

a: \(=4,86\cdot10=48,6\)