[size=4][align=center]9×0+1=1 9×1+2=11 9×12+3=111 9×123+4=1111 9×1234+5=11111 9×12345+6=111111 9×123456+7=1111111 9×1234567+8=11111111 9×12345678+9=111111111[/align][/size]