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From: francis@arthur.uchicago.edu (Francis Stracke)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Why can't the Mac add?
Message-ID: <1990Sep26.232642.18533@midway.uchicago.edu>
Date: 26 Sep 90 23:26:42 GMT
References: <45060@apple.Apple.COM> <20360@dime.cs.umass.edu> <45108@apple.Apple.COM>
Sender: news@midway.uchicago.edu (News Administrator)
Organization: Mathematics Department, University of Chicago
Lines: 17

In article <45108@apple.Apple.COM> das@Apple.COM (David Shayer) writes:
>huh-HUM (throat clearing noises.)
>The calculator DA can do this math correctly.  If you add 0.2 fifty
>times, you get 10.0.  Exactly.  Not 9.999999 or 10.0000001.
[...]
>Does the calculator DA have its own special math package?  (If so, the
>dCad calculator does too.)  No one seems to think SANE has calls which
>take care of this.  So why does it work in the calculator?

What are you asking us for? Find the source code & take a look! What's the
point of working for Apple if they won't let you at stuff like that?

(BTW: it's not just a simple BCD package.  Try this: 2/3-.66666666667
(I think that's right: however many 6s it shows you from 2/3).  You get
-3.33333E-12.  So it's a lot more accurate than it looks.  Either they
used SANE in some weird way, or they put a LOT of digits into their BCD
package, many more than needed.)