To add to Bob's reply:
The value must be entered as '0500450002883 to preserve the leading zero
To check if remainder equals 13th digit:
=MOD(SUMPRODUCT(--(MID(A17,ROW(INDIRECT("1:12")),1)),ROW(INDIRECT("1:12"))),
9)=VALUE(RIGHT(A17))
The INDIRECT is not needed unless you plan to copy the formula to other
cells
=MOD(SUMPRODUCT(--(MID(A19,ROW(1:12),1)),ROW(1:12)),
9)=VALUE(RIGHT(A19)
best wishes
Bernard V Liengme
www.stfx.ca/people/bliengme
remove caps from email

"Bob Phillips" <phillips@tiscali.co.uk> wrote in message
news:eXFluRHjFHA.3436@tk2msftngp13.phx.gbl...
> =MOD(SUMPRODUCT(--(MID(A17,ROW(INDIRECT("1:12")),1)),ROW(INDIRECT("1:12"))),
> 9)
>
> --
> HTH
>
> Bob Phillips
>
> "Lowkey" <Lowkey@discussions.microsoft.com> wrote in message
> news:C91D97FE-175A-471D-BDE0-F1ECB6651AC3@microsoft.com...
>> I am trying to create a check digit worksheet for an algorithm where
>> staff
>> have to use the algorithm hundreds of times daily, so it has to be quick
> and
>> efficient.
>>
>> The algorithm works where the first 12 digits are multiplied and summed
>> using simple math, and the REMAINDER of the of the sum divided by 9 must
>> equal the 13th digit.
>>
>> For example:
>> My number is 0500450002883, so
>> 1x0=0
>> 2x5=10
>> 3x0=0
>> 4x0=0
>> 5x4=20
>> 6x5=30
>> 7x0=0
>> 8x0=0
>> 9x0=0
>> 10x2=20
>> 11x8=88
>> 12x8=96
>> where the sum = 264. If you divide 264 by 9, the remaider is 3, the check
>> digit.
>>
>> What formula can I use to produce the remaider for 264/9 instead of
> getting
>> 29.33?
>>
>
>