If the data is in exactly the same position in the two worksheets you could
copy/paste one's data to a new worksheet and then copy the second's, doing
an Edit, Paste Special, Subtract on top of the first's data. This is
admittedly crude but it is easy to do.

--
Jim Rech
Excel MVP
"cursednomore" wrote in message
...
|I have two workbooks (2005 Sales, 2004 Sales), which track daily results in
| half hour intervals. I want to be able to show the increase in 2005 in a
3rd
| workbooks. The first two workbooks are identically formatted. How can I do
| this? Many thanks to all in the forum who have helped in the past.