You know, there could have been plot, or character development, or something funny, but when you have such a popular comic, these kinds of juvenile ideas must come first. Most of the readers are adolescent boys (mentally or physically), after all.
Jesus, Marvin, how many setup strips do you need for the joke "Marvin's Dad is a giant nerd"? I know that when you have to do seven strips a week, thinking of a new drawing and joke for each one is a bit of a chore. But you know, that's what they pay you for. Doing the same exact joke three or four days in a row, with almost the same picture over and over is just... the reason why newspaper comics are dying.
(x, why) bores us with yet another pun that has to do with math. It's just not very clever, or funny. I'd like to give some points for originality - I haven't seen this idea before. So I will give points for that. But the jokes in this comic always sound too much like "I am now going to be funny. Wait for it.. here it comes! Now laugh!"