Try instead of using average...

=(Sumif(A1:A22,"0",A1:A22)/Countif(A1:A22,"0"))

This sums all values that are numbers, then divides by the count of all
values that are numbers... which gives you the average

"Pedro S." wrote:

How can I get the €œ<€� and €œ€� symbols act as part of a number on a formula?

I work at a lab, and when we get results that our equipment can not measure
the samples, we use the €œless than€� symbol€¦ The problem is that when you
write a formula at the end of the column; for example get the average of
A1:A22, if any of the cells contains a €œ<€� symbol, the result should also
have €œ<€� with the number.