Sorry, I'm a bit confused between your two postings. In your first post
you seem to be saying that if every A2 cell on the seven sheets is
blank, then you want the sum of all the C2 cells, otherwise you want
zero (so if you have only 6 or fewer blanks then you want a zero).

Now you seem to be saying that if A2 is blank on any sheet, then add C2
from that sheet (so if you have 5 blanks, then you will have five C2
cells added together).

Which is it to be?

Pete