Computer Science for IGCSE & O level - Data Transmission (Section 2 - No. 15)
What is the general formula used for the calculation of the check digit in an ISBN-13 number?
Sum of all digits, modulo 10.
Weighted sum (alternating 1 and 3), modulo 10.
Weighted sum (all weights 1), modulo 11.
Product of all digits, modulo 10.
Εξήγηση
The check digit calculation uses a weighted sum with alternating weights of 1 and 3, and then a modulo 10 operation is performed.