Calculation

[tkosel]

This is actually my second post, I neglected to show the data I was asking
about.

If i have the following data in a worksheet (first 20 rows), it yields the
sum calculation in row 21. How can that be? How can it have more resolution
than the source data. I expect it to be zero. (Obviously i have displayed
more decimals in row 21 than the others.)

-0.00635
-0.0437
-0.0092
0.0276
0.0115
-0.05175
0.0805
-1.14955
1.2742
0.06925
-0.277
0.9695
-0.59555
-0.0762
0.0254
-0.1016
-0.17145
0.508
-0.48475
0.00115
-0.000000000000000095409791178724