I was telling my math class the story about how Gauss added up the numbers from one to a hundred when he was in first grade. I told them that when he put his slate on the teacher's desk face down, the teacher thought he was some kind of smart alec. And then I told my class that the Germans have very picturesque words for a lot of things, and they probably have a nice expression for "smart alec". And now I can't think of one. Can anyone help?
EDIT: As a matter of secondary interest, my Yiddish correspondents have offered me the very colorful "khokhem", lit. "wise man" from the Hebrew khakham. (A Karaite rabbi is a khakham.) A variant is "khokhmah", as for example if a child learns to make a loud slurping noise when drinking with a straw, his mother might say he's got a new "khokhmah". As far as I can see none of the German expressions would have had much currency in spoken Yiddish, although they would of course have all been understood by any Yiddish speaker.