Why is it important to check that your answer is reasonable? We often use calculators to solve problems with large numbers. It is not unusual that a person will enter incorrect numbers or miss a digit when entering and answer from the calculator screen. Use estimation and common sense to guide you.

In this unit, you will use tree diagrams and develop counting methods. You will develop ways to count in situations when the order of items is critical. You will see how to recognize unordered selections as combinations, and develop ways of counting when the order of items is not important. You will learn how to calculate probability, use experiments to find probabilities, and what affects the probability of an event. You will learn to determine which events are dependent, and which are independent.

Terms needed for this unit are: