Peco, did you mean to post that reply to a different question? I don't understand what it means in this context.

(In fact, I don't know what "finction" is.)

Rabend, I don't use the filter much but as I understand it it's intended to be a way of viewing details; as you're saying yourself, it doesn't have an effect on the SUM function, nor on any other function so far as I know.

I take it you want a sum of only those 3s that appear in certain cells, and you can do that but you'll need either SUMIF or COUNTIF. Do you know already how to do that, or shall I explain?

And by the way, as I said I don't use filters much so if someone else here knows that I'm mistaken about them not affecting functions, please chime in.