The article below from PC Magazine may be of interest to those of you
who use Excel 2007
Bill B.
========================================
We all learned how to multiply with pencil and paper, even great big
numbers and decimals. But when it comes to something important like a
blueprint or a
scientific formula we reach for a calculator - or a spreadsheet. That's
much
more reliable, right? Well, not if the spreadsheet is Excel 2007. Over
the
weekend a member of the microsoft.public.excel newsgroup revealed that
Excel
2007 thinks that 850*77.1 is 100,000. What's the correct answer? Anybody?
Anybody? Bueller? Anybody? Right, it should be 65,535. Other members
verified
that the error carries over into some (but not all) calculations based on
the
incorrect result. Microsoft has been informed of the bug, but hasn't yet
formulated a response.
UPDATE: Microsoft recognizes the problem and assures us that Excel
Will Learn to Multiply.
If it were just 850*77.1 that gave a wrong answer, we could probably
work around that. But there are tons of other problem numbers, as I
discovered for myself. I set up a spreadsheet to divide 65,535 by
every number from 1 to 65,535 itself, then multiply the number by
that result. So, for example, it
divided 65,535 by 26 to get 2,520.577. Then it multiplied 26 by 2,520.577
to
get... 100,000?! Over ten thousand of these simple calculations gave the
wrong
answer.
We won't know just why the problem comes up until Microsoft speaks
out, but there is one thing about 65535 - it's the very largest
16-bit number. In binary it's a string of 16 ones. In hexadecimal
(the programmer's friend) it's
FFFF. But converting the "problem" results to hexadecimal in Excel yields
FFFE. That's surely a clue. Meanwhile, if you have any spreadsheets where
some
results hit the range around 65535, it might be a good idea to
double-check
with your trusty calculator... or a pencil.
