Hello,
I have a formula in excel that I am using to come up with the check digit in excel like this:
=MOD(10 - MOD( SUMPRODUCT(MID(A2, {1,2,3,4,5,6,7,8,9,10,11,12,13}, 1) * {3,1,3,1,3,1,3,1,3,1,3,1,3}), 10), 10)
where A2 is equal to 2001234567890
after the calculation i come up with =9
I...