Take a look he

http://cpearson.com/excel/rounding.htm


The problem *is* rounding, but it's inherent in the way IEEE double
precision floating point math is done (on all spreadsheets).

In article ,
pod wrote:


To test, type in a value in cell A1, and then click on the first button to
spread the values, and then the second button to compare the results of A1
with A3. One number in particular that doesn't work is 12.825. (I know that
some other numbers don't work because of rounding, and I can get around
that,...but there is no rounding involved when using 12.825).