|...| |..|. |.... ...|| ..|.| ...|| ||... |..|. ..|.| .|..| 7 8 ? 1 2 1 0 8 2 4We know there is an error for the third digit, since no digit is represented by code with only one long bar. We can find out what the third digit should have been by picking it so that the sum of the digits is an even multiple of 10: 7 + 8 + ? + 1 + 2 + 1 + 0 + 8 + 2 + 4 = 33 + ?, so ? must be 7.
8 8 8 8 8 8 8 8 8 8 8 8
8 8 8 _{.} 8 8 8 8 8 8 8 8 8