Technically there aren't any levels in the anime. It would appear that they used this as a way for real life viewers to know the answer and basically play along with it in their heads. Keep in mind pokemon anime is directed at younger children; the ones who do know the answer and watch the show will be able to pretend they are a "pokemon master" as if it were a question and answer program from a children's show. The rules of pokemon in the anime has never been made clear and as after all this time ash is still the same age as, you can probably see why!
Hope this helps :D