On Mar 8, 4:21 pm, "Roger Govier"
wrote:
=AVERAGE(ESP1!F24+ESP2!F24+LV!F24+LA!F24+RAT!F24+S F1!F24+
SF2!F24+SF3!F24+TA*OS!F24)
then if they sum to 0, you will get the #DIV0 error message

Are you sure? Works fine for me when all cells are on the same sheet.