GnuCash can't add?

[Mike or Penny Novack]

>Yes, this looks like a rounding error.  Or, more accurately, it's a
>cumulative rounding error. 
>
And by "error" we don't mean a bug in the software.

This is the sort of "error" with which we should be familiar. Suppose 
for example you are required to enter numbers in some governmental form 
in "whole dollars" (or whatever currency) and these are supposed to 
match some total also in whole dollars.

item 1:      37,241.43      37,241
item 2:      12,311.35      12,311

sum          49,552.78      49,553

But 1 + 1 doesn't equal 3!  You might imagine at first that no big deal 
since the see only the whole dollars? (and not what's on your books). 
Not so. It might be required that some sum total now match the total 
from a previous year plus changes and both of those year end totals 
might need to match some official number (like the balances on certain 
dates in an account).

One of the jobs I used to do, beyond most programmers to figure out, was 
the maximum "fuzz" which could result from "rounding errors" in a 
particular set of calculations so that two numbers within this "fuzz" of 
each other were to be considered the same in a test for "equal". You 
don't want the "fuzz" to be any larger than it must nor too small 
causing errors because "not equal".

Michael