Math 108 Topics in Mathematics | Section 1000 | Laura Barnes |
16.1 Bank Checks and Codabar - Video

16.1 Bank Checks and Codabar - Video

Key Ideas

A variation of UPC uses a similar sum with weights 2 (odd positions) and 1 (even positions). This
codabar scheme is used for credit cards. Specifically, the Luhn algorithm takes the sum and adds the number of digits in odd positions that exceed 4; the resulting number must end in 0 to be a valid code.

Bank check scheme 7a_{1}+3a_{2}+9a_{3}+7a_{4}+3a_{5}
+9a_{6}7a_{7}+3a_{8}. The last digit of the sum is used as the check
digit a_{9}.