Six, Seven, and Nine

Alright, Lord Voldemort, you big scary magic man who also has no nose and is afraid of a baby, listen up. This joke relies on a pun, okay? It's playing on the phrase "three square meals," but twisting it using math. Like, seven "ate" nine, but it should be that seven squared is forty-nine. It's not that complicated, but I guess you, who is only good at magic and being scary, would not understand. Get it?