10 May 2011

Proof of why a transposition error is always divisible by 9

Here's a little proof I knocked up over the weekend. Sorry it's in a picture format, the platform on which this blog is based can't deal with simple mathematical symbols, so I had to convert a document into a couple of pictures. If you click on the pictures, you should be able to see a larger version of each of the two pages of the proof.

3 comments:

  1. Please note, there is a deliberate error in here, so if you copy it verbatim it won't be watertight. If you want to correct it, you first have understand the error. ;-)

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  2. Anonymous13 July, 2011

    Do you know who first made this known or who discovered the transposition error rule of divisible by 9?

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  3. Sorry, no idea on that one. It just seems to be "one of those things."

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