Actually, he's using completely appropriate terminology. Your mathematical education is just sufficiently limited that you don't know that. Rather than getting

Actually, he's using completely appropriate terminology. Your mathematical education is just sufficiently limited that you don't know that. Rather than getting angry, you'd think your reaction would be to absorb the new information. To me, your complaint is like someone saying it's inappropriate terminology to discuss time complexity in big-Oh notation, because we're programmers, not mathematicians.