ISBN Check Digit Code

[ne012]

The sixth digit in the ISBN 0-7923-519-X was blanked out. Find the missing digit.


The answer is 7, however I am not sure how to arrive at this answer. Can someone please provide a step by step explaination on the method involved to solve the problem?

Thanks

 

[keith1200rs]

Are you sure it's 7? This says it's 8:

https://www.morovia.com/education/utility/upc-ean.asp

The DIY method is here:

https://en.wikipedia.org/wiki/International_Standard_Book_Number


Keith.

 

[ne012]

Are you sure it's 7? This says it's 8:

https://www.morovia.com/education/utility/upc-ean.asp

The DIY method is here:

https://en.wikipedia.org/wiki/International_Standard_Book_Number


Keith.

The answer is 7!

 

[keith1200rs]

I don't actually understand how you have an ISBN with no 6th digit. However, given you now have the equations you could re-arrange them to get any "missing" digit.

Keith.

 

[bassa]

you may check the following method

The sixth digit in the ISBN 0-7923- 519-X was blacked out. Find the missing digit.
The missing digit x6 satisfies the equation, modulo 11,
0 = 1 · 0 + 2 · 7 + 3 · 9 + 4 · 2 + 5 · 3 + 6 ·x6 + 7 · 5 + 8 · 1 + 9 · 9 + 10 · 10
= 6x6 + 288 = 6x6 + 2 = 6x6 − 9 .
The solution to 6x6 = 9 mod 11, found by trial and error, is 7. The complete ISBN is 0-7923-7519-X.
(The book is JPEG2000, by David S. Taubman and Michael W. Marcellin, Kluwer, 2001.)

regards
bassa