Math Is Fun Forum

So that Ricky's comment above makes sense to everyone here....I include this added description of the problem...

I was asked...what do these numbers represent?

My Response:

they essentially don't represent anything. this comes from an archaic book of unique "designation terms" that would be used to designate between a large inventory of....well whatever (ie each item in would be assigned a unique reference "designation term", the numbers here are the last digit in these "designation terms". all the other digits in the each of these "designation terms" follow a simple pattern that I was able to decipher, only this last digit follows a more complicated pattern.  whoever created this huge old book of "designation terms"probably used a simple algorithm to produce these numbers in large quantity.

Also I thought that....
these numbers' variation have nothing to do with the other digits in these "designation terms" and so you should have all the information you need to figure out this little puzzle.

But based on Ricky's comment above.....

Ricky,
I now know that these are infact check digits, so what you say would make sense. If this is a Luhn formula/algorithm or variation of a Luhn doesn't that imply that you would need the rest of the characters in each "designation term" to solve the puzzle?  Is this correct?

they essentially don't represent anything. this comes from an archaic book of unique "designation terms" that would be used to designate between a large inventory of....well whatever (ie each item would be assigned a unique reference "designation term", the numbers here are the last digit in these "designation terms". all the other digits in the each of these "designation terms" follow a simple pattern that I was able to decipher, only this last digit follows a more complicated pattern.  whoever created this huge old book of "designation terms"probably used a simple algorithm to produce these numbers in large quantity.

these numbers' variation have nothing to do with the other digits in these "designation terms" and so you should have all the information you need to figure out this little puzzle.

and so essentially, you shouldnt need any background info, but there's a little for ya.

Happy Puzzling!