998^2+9980+16
=(1000-2)^2+9980+16
=1000*1000-4*1000+4+16+9980
=1000000-4000+10000
=1006000
998^2+9980+16
=998^2+10x998+16
=(998+2)(998+8)
=1000x1006
=1006000