## Lesson: Finding Probability

Developing the Concept

Now that students have had an opportunity to find the probability of simple events by using a sample space or the fundamental counting principle, they can apply these strategies on their own.

**Materials:** 5 red, 3 green, and 2 yellow tiles; a paper bag; paper and pencil for each student

**Prerequisite Skills and Background:** Students should be able to apply the fundamental counting principle in a problem-solving situation.

On the board, write “5 red,” “3 green,” and “2 yellow” to indicate the color of the tiles in the bag.

**Wrap-Up and Assessment Hints**

“What if” questions are good ways to assess the depth of a student's understanding of probability. Most problems, like those you have done, have several factors that could affect the outcome. In those problems, the number of tiles of each color, the number of draws, and drawing with or without replacement are variables that you can alter to assess the depth of students' understanding. Drawing two tiles with replacement is an example of two independent events. The outcome of the first event does not affect the second event. Drawing tiles without replacing them is an example of dependent events. These are concepts your students should become familiar with.