You don't actually need a posh programmable calculator to play games in math class, you can have fun with practically any kind of calculator if you know how to. I have spent hours and hours playing and inventing calculator games, so I think I must share a little bit of my knowledge with you:

**Track and Field** (those who played the arcade will understand this game's name): A simple game if you don't want to think too much. You need a friend and two calculators. Most standard calculators will count if you press "1", "+", "+" and then "=" repeatedly. The goal is to reach a certain number before your opponent does. If you don't have two identical calculators, you can always play against the clock. A friend of mine is able to count up to 500 in a single minute.

**Guess the Random Number**: Not very fun, but good for bets. Some calculators have a random number generator. The goal of the game is to give a good guess at the next random number. (for example, guess the last two decimal digits). An easy way to decide who pays the next round.

**The Amazing Calculator Game**: My favorite, although I guess you have to be a freak in order to actually like this. The idea is very simple: each player must successfully complete "challenges" set by the other player. The general model for a challenge is: given an initial state, reach a given state by pressing a limited number and/or subset of keys. For example, in a Casio fx-82 "Fraction", input "70" and press "shift", and ask your friend to get an error with a single key. (solution: MR/factorial key). There are LOTS of possible challenges like this in $20 Casio calculators (I guess there are even more in expensive calculators) and many of them are really difficult, so it's better to give your opponent three tries.

**Some of my best tricks for Casio "Fraction" and "Equation" series calculators (for the "Amazing Calculator" game):**

Press the open bracket key eighteen times while your friend can't see you, then input a harmless number (2, for example) and ask your friend to get an error with a single key. Of course, the solution is the open bracket key.

Press the "hyp" key while your friend can't see you, and then ask him/her to do anything with trigonometrical functions.

I hope this will be useful for all the calculator freaks all there... (if they exist)