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From: bayes@hpislx.HP.COM (Scott Bayes)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Why can't the Mac add?
Message-ID: <9710004@hpislx.HP.COM>
Date: 25 Sep 90 15:29:26 GMT
References: <45060@apple.Apple.COM>
Organization: Measurement Systems Operation - Loveland, CO
Lines: 12

Another way of telling if a fraction is representable in a binary computer
(actually just another way of stating what Norman said):

First reduce the fraction (pull out common factors).

If the denominator (that's the one underneath the divide line) has a factor
other than 2^n (n is any integer) in it, it can't be exactly represented.

E.g. your .2 = 1/5 = 5^(-1), which is not 2^n, so can't be represented.

Scott Bayes
Hewlett-Packard Company