=SUM(IF(NOT(ISERROR(a1:a7)),a1:a7))
array entered works for me if that helps

"Henrik" wrote in message
...
Hi,

For some reason I can't get the following to work. I have got an array of
numbers in which some observations are #N/A (the equivalent of NA() ).

3
6
8
#N/A
4
#N/A
5

Normally I'd just sum this array by submitting
{=SUM(A1:A7*ISNUMBER(A1:A7))}, but the (arrayed) formula returns #N/A.
What
do I need to do in order for the formula to return the value 26?

Thanks for your help.