It is likely not an error. I'm guessing that your numbers are the results of
formulas. And that you've got those results formatted to display 2 decimal
places.
For example, your formula results in 10.284, but your display shows 10.28.
The cell still contains 10.284 even though .004 appears to have been rounded
off. The SUM function uses the actual value of the cells (10.284) not the
displayed value (10.28). So, it appears that the SUM is off by a few cents,
but it really isn't.
If you truly want to round your numbers off to 2 decimal places, use the
ROUND function instead of cell formatting. Cell formatting only affects what
is displayed, not the actual number.
HTH
Elkar
