The possibility of winning big on a single spin of roulette sets hearts racing all over the world. Everyone knows that the house always wins in the end, or at least that casinos make tons of money somehow. But where does the house edge come from?

In this lesson, students examine the betting and gameplay of roulette to learn about probabilities and odds. They investigate a “fair” game, where each side can expect to break even in the long run… and then understand how casinos get their mathematical advantage.

### Students will

• Calculate probabilities, odds, and payouts for a “fair” roulette wheel, and understand how they are related
• Examine a real roulette wheel, and learn how a casino alters a game to its advantage
• Discuss whether or not it’s possible to win money or break even playing roulette in the long run

### Before you begin

Students should be able to fluently reduce fractions and ratios to simplest form. No prior probability knowledge is assumed, however. This lesson can help introduce both the ideas of theoretical probability and expected value.