Mod## checksum digit - bar coding dilemma

[TorenApart]

Hello all!
Thank you in advance for any help with my current dilemma.

What I am trying to do is make sense of a check digit numeric character from some sample bar codes.

I have tried mod10 and mod43 algorithms, but so far I can't figure out what algorithm is being used to assign the check digit.
Not knowing much about them this stuff is making it very hard for me to make much sense/progress.

Some examples of the bar codes with the check digit on the end are here:
F000001800314253849
F000006000314253846
F000008500314253843
F000009300314253842

Thanks again for any help!
Please let me know if any further explanation will help!

 

[Macropod]

Hi TorenApart,

See: http://www.idautomation.com/

Cheers