There are lots of different check bit algorithms. It look like you values
meet the Luhn algorithm. I did not check the code below that I got from
en.wikipedia.org. You can get more info from Wikpedia.

Public Function ValidateCardNumber(strCardNumber) As Boolean ' MOD 10 check
digit. "Luhn algorithm"
On Error GoTo Err

Dim intLoop As Integer, intSum As Integer
Dim bIsAlternate As Boolean, intProduct As Integer

For intLoop = Len(strCardNumber) To 1 Step -1

If bIsAlternate = False Then
intSum = intSum + CInt(Mid(strCardNumber, intLoop, 1))
bIsAlternate = True
Else

intProduct = CInt(Mid(strCardNumber, intLoop, 1)) * 2

If Len(CStr(intProduct)) = 2 Then
intSum = intSum + CInt(Mid(intProduct, 1, 1)) +
CInt(Mid(intProduct, 2, 1))
Else
intSum = intSum + CInt(intProduct)
End If

bIsAlternate = False

End If

Next intLoop

If intSum Mod 10 = 0 Then
ValidateCardNumber = True
Else
ValidateCardNumber = False
End If

Exit Function

Err:
MsgBox "Error in ValidateCardNumber()" & vbCrLf & Err.Number &
Err.Description
End Function


"Abdul" wrote:

Dear all,

I have the following serial numbers:

41078928128
41078928136
41078928144
41078928151
41078928169
41078928177
41078928185
41078928193
41078928201

The last digit is a check digit. How can I get the formula /algorithm
to get the check digit? So that if I have the serial numbers I can add
the check digit with it?

Thanks