Sorry, you don't need the +0... use:
{=SUM(A2:A4*B2:B4)}
I noticed that you asked a similiar question
earlier. Is this starting to make sense?
Michael:
Mark's formula will work if you are indeed dealing only with 1's and zeros. If you dealing with zero and any other number you will need:
=SUM((A2:A4*B2:B4)+0)/(A2*A2)
If zero doesn't even play a role in the real situation, the way around that is in a third column use something like this:
(Starting in cell C2):
=if(A2=B2,1,"")
copy that cell down corresponding to the last row for columns A & B.
At the end of column C, write a sum to count all the matches.
There is still one problem with this suggestion and that is that it doesn't take into consideration which column had the undesirable value.
In that case, yet another formula will be needed.
Kevin
Kevin, you lost me. What does "/(A2*A2)" accomplish?
If I was dealing with zero and non-zero values I'd
use...
{=SUM(IF(A2:A4,1,)*B2:B4)}