"Blake" wrote:
How do I average the following column:
1
2
3

4
5
6
The blank row after the three should also be counted
as zero. However I have a very large spreadsheet,
and I don't want to go back and enter zeros in all of
the blank cells.

Use the following array-entered formula (press ctrl+shift+Enter instead of
just Enter):

=AVERAGE(IF(A1:A1000="",0,A1:A1000))

If all of the "blank" data are truly empty cells (no constant and no
formula, not even the null string), you might be able to use the following
array-entered formula (again, press ctrl+shift+Enter instead just Enter):

=AVERAGE(--A1:A1000)