Reverse mod-10 security digit calculation

can anyone assist with what type of check digit calculator is used to get the 9th security check digit from this set of numbers? the numbers are 521790544 and the security digit is 4. So the security digit is calculated from 52179054. I dont need the security digit, just the algorithm for how it was calculated. thanks.

According to this article, you need to know what the original offset was to decrypt:

So it looks like you also need it to get the checksum