I suppose this would work, there will be problems though if the next
time you run the code the the last sum wasn't cleared so this code
will clear it first.

Dim s As Range

Set s = Range("A65536").End(xlUp)
s.ClearContents 'clears the last entry in Column A

Range("A9").End(xlDown).Offset(2, 0) = _
Application.Sum(Range(Range("A9"), Range("A9").End(xlDown)))