banking&FP

[Gideon Yuval]

You don't have try very hard before bankers can get surprised:

On any spreadsheet handy, start with $18.12, subtract $10, then $8,
then 10 cents, then 2 cents.

(1) Can you explain the result to your friendly neighbourhood banker?

(2) (harder!) Can you _justify_ the result to your friendly
neighbourhood banker?

N.B. It is easy to make the result _look_ right, by "appropriate"
formatting; but you then get a number that looks like a zero, but is not one.
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From: M. Douglas McIlroy  <netmail!dougaresearch.att.com>
To:  <validgh!numeric-interestauunet.UU.NET>
Date: Tuesday, October 06, 1992 12:04PM

Contrary to rumor, bankers often use floating point.
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