Question

Tính nhanh

a)639+1999

b)5219+6998

c)4996+2314+1003

Answer 1

a) 639 + 1999

= (639 - 1) + (1999 + 1)

= 638 + 2000

= 2638

b) 5219 + 6998

= (5219 - 2) + (6998 + 2)

= 5217 + 7000

= 12217

c) 4996 + 2314 + 1003 

= (4996 + 4) + (2314 - 4) + 1000 + 3

= 5000 + 2310 + 1000 + 3

= (5000 + 1000) + (2310 + 3)

= 6000 + 2313

= 8313

Answer 2

a/1999 + (1+638)

=2000+638

=2638

Answer 3

Tính nhanh

a)639+1999= 2638

b)5219+6998=12127

c)4996+2314+1003=8313

 -- bấmmáytínhthìcáigìcũngnhanh--

Answer 4

a) 639+1999=(638+1)+1999=638+(1+1999)=638+2000=2638

b) 5219+6998=(5217+2)+6998=5217+(2+6998)=5217+7000=12 517

c) 4996+2314+1003=4996 + (2313+1)+(1000+3)=(4996+1+3)+1000+2313=5000 +1000+2313=8313

Answer 5

b/6998 +( 5217+2)

=7000+ 5217

=12217

Answer 6

a) 639 + 1999

= ( 639 - 1 ) + ( 1999 + 1 )

= 638 + 2000

= 2638

b) 5219 + 6998

= ( 5219 - 2 ) + ( 6998 + 2 )

= 5217 + 7000

= 12217

c) 4996 + 2314 + 1003

= ( 4996 + 1 + 3 ) + ( 2014 - 1 ) + ( 1003 - 3 )

= 5000 + 2013 + 1000

= 8013

Phần c) thì mình không chắc chắn lắm đâu ,
Học tốt nhé bạn !

Answer 7

c/4996+(1003+1)+(2314-1)

=(4996+1004)+2313

=6000+2313

=8313

Answer 8

a) 639 + 1999

= ( 639 - 1 ) + ( 1999 + 1)

= 638 + 2000

= 2638

b) 5219 + 6998

= ( 5219 - 2 ) + ( 6998 + 2 )

= 5217 + 7000

= 12 217

c) 4996 + 2314 + 1003

= 4996 + ( 2314 - 1 ) + ( 1003 + 1)

= 4996 + 1004 + 2313

= 6000 + 2313

= 8313

=