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From: hansm@cs.kun.nl (Hans Mulder)
Newsgroups: comp.misc
Subject: Re: ISBN checksum
Message-ID: <3564@wn1.sci.kun.nl>
Date: 21 May 91 11:27:13 GMT
References: <1991May19.022623.2905@solbourne.com>
Sender: root@sci.kun.nl
Organization: University of Nijmegen, The Netherlands
Lines: 12

In <1991May19.022623.2905@solbourne.com> imp@solbourne.com (Warner Losh) writes:
>Does anybody know the checksum procedure for ISBN book numbers?

1 * 1st digit + 2 * 2nd digit + 3 * 3rd digit + ... + 10 * 10th digit
must be divisible by 11.

Sometimes the last digit is an 'X'; that's a Roman digit with value 10.

--
Have a nice day,

Hans Mulder	hansm@cs.kun.nl