I would very much like to see the data. Could you email me a file? Please
get my email from my website
best wishes
--
Bernard V Liengme
Microsoft Excel MVP
http://people.stfx.ca/bliengme
remove caps from email


"hou" wrote in message
...
when I use the Sum function to calculate about 10,000 numbers, which have
been rounded to 2 decimals (using the round function in excel), the result
of
sum came out with more than 2 decimals. It is eight decimals!
I don't know why, and I split the numbers into several groups. I find that
an interesting thing, the sum of Group A has two decimals, the same with
Group B. But when I calculate the sum of the two groups, the result also
came
out with 8 decimals!!!...