Need help with formula for vlookup/multiple sheets/adding excluding NA's

[jim5309]

I am in excel 2010. I have jan-dec of 2010, 1 month per sheet. Some months have all locations, and some do not. I simply want to do a summary page that says 'add all the volume for this facility from each tab' but for some reason I keep getting NA's. Say a plant in california has sales only in 10 of the 12 months. This will return a NA on the summary page. I still want it to vlookup the plant in all sheets and add everything together wherever it sees it. Any help would be appreciated.

 

[AlphaFrog]

You can eliminate the N/As with the IFERROR function

=IFERROR(your_formula_here, "")