I have a simple sum function at the bottom of a column:
=SUM(D4:D68)

About half of the cells in that range are empty. When I add data to the
empty cells the SUM total in cell D69 does not update. It remains static. I
have to manually re-SUM every time. I've never had this problem before - I'm
sure some formatting issue but I don't know what. Would appreciate any help.
Thanks.