Assuming column C is available, otherwise use another that is and that range
for stuff in A is A1:A9800, and that range for B starts in row 1 also,

in C1 put:
=Countif(A$1:A$9800,B1)
and fill down to the end of the stuff in B - this will give you a count of
the number of times the value in B appears in A.


"GARY" wrote:

How can I determine which cells in Column A contain the same contents
as cells in Column B?
(Column has 9,800 cells; Column B has 3,600 cells).