Bug in excel?

[Svante]

Dear excelgurus,


I have a list of 20 values with no more than 2 decimal places.


When these are summed, the sum is -0.000000000083673512563109400, which I think should be mathematically impossible when none of the summands have more than two decimal places.


Is this an excelbug?


One would think that it is in Microsoft's interest to have potential bugs identified so I contacted Microsoft but they did not want to see or investigate the bug unless I paid $100 (of course I have a valid Microsoft Office license).


If this is an error it could reasonably have serious consequences in sensitive calculations.


Below is the list of values and at the bottom the sum I receive using "autosum".


7 841,00

-7 837,50

-655 796,02

-677 805,67

-160 767,67

-7 959,15

-12 808,00

-13 285,60

-1 792,00

-48 041,97

-4 116,00

-1 008,36

-50 936,80

-712,80

-7 308,48

-724,00

5 019,69

2 046 772,00

-411 049,01

2 316,34

-0,000000000083673512563109400


Link to exceldocument http://dl.dropbox.com/u/722403/Excel%20bug.xlsx


Do you have any reasonable explanation of this?


Thanks in advance!


//Svante

 

[kchiba]

Hi


Check this link


http://office.microsoft.com/en-us/excel-help/set-rounding-precision-HA010218870.aspx


You can also Google "Number Precision in Excel", this will give you a number of articles on the subject.

 

[Svante]

Thanks kchiba for a quick response, I will check that!