Has anyone had any experiences with a hidden decimal value in Excel. I essentially have three numbers with no value beyond the hundredth decimal place that when added yield a sum with a value in the 9th decimal space. The following is what the numbers look like when I copy and paste as values, extend the decimal places to the maximum 30 spaces and sum the 3 numbers.

3,426,429.870000000000000000000000000000 (This value is entered manually)
1,084,762.460000000000000000000000000000 (This comes from a sum formula output)
-5,413,327.380000000000000000000000000000 (This comes from a sum formula output)
-902,135.050000001000000000000000000000

If I manually key in these three numbers and sum them, the trailing decimal value does not show up in the sum. It's just when I copy and paste as value from a formula that apparently a hidden decimal value sneaks in.

Yes, this can happen (due to binary computation). You can round the result to n decimal places using one of Excel's rounding functions.

Jeesh, that's kind of junk. No big problem with my situation rounding but if I was working with numbers with extended decimal spaces I would question the accuracy. It's just strange that the number displayed may differ from the number used if you referrence that cell in a formula.