1996+3992+5988+7984
= (1996+7984)+(3992+5988)
= 9980+9980
= 9980x2
= 19960
1996 + 3992 + 5998 + 7984
= ( 1996 + 7984 ) + ( 5988 + 3992 )
= 9980 + 9980
= 9980 x 2
= 19960
1996+3992+5988+7984
=(1996+7984)+(3992+5988)
=9980+9980
=19960
Nhớ
=(1996+7984)+(3992+5988)
=9980+9380
=19360