A check digit is a form of redundancy check used for error detection on identification numbers, such as bank account numbers, which are used in an application where they will at least sometimes be input manually. It is analogous to a binary parity bit used to check for errors in computer-generated data.
How do you find the check digit?
Check digits
- The first, third, fifth and seventh numbers are each multiplied by three, and then added together.
- The remaining numbers are added to the total.
- The total is divided by ten.
- The check digit is determined by subtracting the remainder from ten.
What does check digits mean?
A check digit is a number added to each character in a coded system which allows for the detection of errors; through the use of a mathematical formula, recording errors such as number reversals can be noted. See parity bit.
