Thanks Niek,

In that document it says: "Excel 97, however, introduced an optimization
that attempts to correct for this problem. Should an addition or subtraction
operation result in a value at or very close to zero, Excel 97 and later will
compensate for any error introduced as a result of converting an operand to
and from binary. The example above when performed in Excel 97 and later
correctly displays 0 or 0.000000000000000E+00 in scientific notation."

I'm running in Excel 2002 but still getting this problem. The number is very
small so I would have thought it would have applied to this opitization.

Thanks for your help though,

Alex.

"Niek Otten" wrote:

Hi Alex,

See

http://support.microsoft.com/default...kb;en-us;78113

--

Kind Regards,

Niek Otten

Microsoft MVP - Excel

"Alex Andronov" <Alex wrote in message
...
I believe I have found an excel bug.

To replicate it put the following simple formulae in excel.

In A1 put: 2.7
In A2 put: -4.3
In A3 put: 2.2
In A4 put: =5.2+(-5.8)

In A6 put: =sum(A1:A4)

If you make A6 show as many decimal places as possible you will suddenly
discover a very small number is being produced. Oddly if you set A4 to
contain -0.6 then it solves the problem.

Any ideas what's going on?

Alex.