1, 2, 8 and 9

Views:

9 x 2 = 18

99 x 2 = 198

999 x 2 = 1998

9999 x 2 = 19998

99999 x 2 = 199998

999999 x 2 = 1999998

9999999 x 2 = 19999998

99999999 x 2 = 199999998

999999999 x 2 = 1999999998