Find if value in column A exists in Column B

Hi there - I have 2 columns of data (numerical), I need to find how many
values exist in both columns. Some type of lookup function should do it, but
I tried and was unsuccessful. Can anyone help?

Try:

=SUMPRODUCT(COUNTIF(A1:A10,B1:B10))

HTH
Jason
Atlanta, GA

>-----Original Message-----
>Hi there - I have 2 columns of data (numerical), I need
to find how many
>values exist in both columns. Some type of lookup
function should do it, but
>I tried and was unsuccessful. Can anyone help?
>.
>