From: "Andy Robertson" 
Subject: Re: (urth) Base 9 on the Whorl?
Date: Sun, 12 May 2002 09:05:39 +0100

----- Original Message -----
From: "Robert Borski" 
> Yes. But if indeed the children are making mistakes, they are making the
> less likely one. 29 - 19 in base 10 is almost impossible to get wrong--

It is 10 in any base whatever.


> our solution. But a calculation in base 9 of 7 + 17 is much more
difficult,
> even for adults; you need to figure out (or memorize by rote) that the
> number 17 only contains 16 integers

No, no,no.   All you need to know is that 7+7 = 15.     You put 5 down and
carry 1 making 25.

It's a fascinating idea, Robert, but there is no evidence for it.


   hartshorn



(I did teach my kids base 9 - as a mental exercise for them)


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