Date   : Sat, 18 Feb 1984 14:58:35-EST
From   : Larry Seiler <Seiler@MIT-XX.ARPA>
Subject: Floating point money

FLoating point numbers are the wrong thing to use in what is
essentially an integral application (integral numbers of pennies).
Although there are ways around this - such as rounding values to 
the nearest penny before comparing them.  If you want ease of use
for those MBA's (a worthy goal, certainly), then print out numbers
and let them type numbers with two digits past the decimal point, 
but store all numbers internally as numbers of pennies (the MBA's 
won't be writing programs, just using them).  And keep those MBA's 
away from Multiplan.  While I love Multiplan dearly, don't expect 
it to work any better than Turbo Pascal on floating point comparisons.  
In fact, my copy of Multiplan (for the VT180) can't even round zero 
to two decimal places and get something that is equal to zero (details
on request).  Number representation is a tricky problem, I'm sorry to say,
and I'd hate to use a tax program written by someone who couldn't see
what the problem is.
       Larry