999*274+6274
=999*274+6000+274
=274*(999+1)+6000
=274000+6000
=280000
54+999*999+45
=99+999000-999
=999000-900
=998100
8+88+888+8888+88888+88888
=8*(1+11+111+1111+11111+111111)
=8*123456
=987648
999*274+6274
=999*274+6000+274
=274*(999+1)+6000
=274000+6000
=280000
54+999*999+45
=99+999000-999
=999000-900
=998100
8+88+888+8888+88888+88888
=8*(1+11+111+1111+11111+111111)
=8*123456
=987648