For all you people who draw graffiti in Math/Physics class and want something more important to do with your time, I suggest you try these awesome calculator games.

Pheonix: A game a lot like Space Invaders, except you can buy new weapons, upgrades, helpers, etc. Galaxan(and Galaxan 2) are a lot like this game.

Uncle Worm: An awesome game akin to Snakes, except your a line and you can move in many more directions. Bytes is similiar to this game.

ZTetris: I think you all know what this game is.

Fall Down: Literally, you try to fall down holes before the calculator catches up to you, the best game because you can go back to "graphing" with one click of a button :p.

Bomberkids: Like bomberman this game is for play between 2-4 people. Tell your teacher your transfering "data".

JUST please never play these at home!

Oh yes, and you do need a Graphing Calculator to play these (I have a TI-83)