Probability is the branch of mathematics concerned with analyzing the chance that a particular event will occur. The basic purpose is to predict the likelihood that something will or will not happen. Probability can be calculated on the basis of observing the number of actual outcomes and the number of possible total outcomes.

Sometimes without even thinking we make decisions based on our ideas about the likelihood of an event happening. For example, if a weather forecast tells you that there is a 90% chance of rain, you might decide to carry an umbrella. On the other hand if you know that the risk of an airplane crash is maybe one in a million, you might decide that is a risk worth taking. Understanding how probability works is important so that we can make informed decisions.

Many of you may have first hand experience with a friend being injured while participating in a sport. If your were considering participating as well, what evidence would you want to consider in making your decision? Would you decide not to participate based on the one case of your friend? Discuss this situation with your group and be prepared to discuss your reasoning.

In many areas of science, such as genetics, scientists have to collect a lot of data and apply probability to help predict an outcome. The Law of Large Numbers predicts that a small number of trials will yield a wide range of results, which may or may not be close to the expected probability. It also predicts that a large number of trials will yield results closer to the expected probability. Numbered cubes in various forms are found in many parts of the world and have been used in both ancient games of chance and modern games like Monopoly. You can use your computer and numbered cubes to test whether the Law of Large Numbers seems to hold true.