On a seperate cell insert the value 15
Copy that value (15).
Highlight the cells you want to add the 15 to.
Click on Edit - Paste Special
Underneath the Paste section Select "Formula"
Underneath the Operation section select "Add"
Click OK

That should add 15 to all the cells you selected. Feel free to delete the 15
you inserted on a seperate cell it wont affect the formula you just pasted.

"Veriel" wrote:

I have a spreadsheet showing the costs of shipping via UPS on all zones for
several different weights. I need to add $15 to all the costs as our
surcharge for handling. Please help with a simple formula to add 15 to all
selected cells.