Check digit calculation of Modulo 11
This is a description of calculating check digits according to Modulo 11. ActiveBarcode calculates this check digits for most codes automatically.
Calculating a check digit according to Modulo 11:
Modulo 11 is e.g. used by PZN. Here are some examples of how to calculate the check digit according to Modulo 11:
Calculating the the check digit of PZN: Multiply the first digit by 2, the second digit by 3, ... the sixth digit by 7. Add the results and divide it by 11 and the remainder (Modolu 11) is the check digit. If the check digit is a "10", the PZN is not released as it is not considered valid.
Here is an example:
The ISBN-10 and ISSN check digit: With this check digit system it is possible for the check digit to be 10. In this case the X is used like in this ISBN: "3-928444-00-X".
Here is an example for the ISBN-10: