1. Put -20 in an open cell.
2. Copy that cell.
3. Select your range of data.
4. Go to Edit Paste Special and select "Add".
5. Press OK.

HTH
Jason
Atlanta, GA

-----Original Message-----
for example:
i have a row with 20,40,50,80,120
and i want it to be 0,20,30,60,100 (so all -20)

how do i do this?
.