I'm trying to create a formula to sum a range of cells, like A1:A10,
but only if all the values are numbers. On occassion I may place the
text "TBD" into a cell and if thats the case I want to sum of the
range to be zero.

This is the latest formula I tried but it didn't work. Any thoughts
would be greatly appreciated.

=SUM(IF(ISTEXT(A1:A10),0,A1:A10))

AJ