# Lesson 9

Multi-step Experiments

### Lesson Narrative

In this lesson, students continue writing out the sample spaces for chance experiments that have multiple steps and also begin using those sample spaces to calculate the probability of certain events. Students may start listing the sample space using one method and then decide to switch to a different method when they get stuck in the middle of the problem (MP1) or they might recognize certain aspects of the situation that would lead them to choose a particular method from the beginning (also MP1). For instance, a problem that involves two spinners would be easy to represent with a table, but a problem that involves three spinners may be easier to represent with a tree diagram.

### Learning Goals

Teacher Facing

• Choose a method for representing the sample space of a compound event, and justify (orally) the choice.
• Use the sample space to determine the probability of a compound event, and explain (orally, in writing, and using other representations) the reasoning.

### Student Facing

Let’s look at probabilities of experiments that have multiple steps.

### Student Facing

• I can use the sample space to calculate the probability of an event in a multi-step experiment.

Building On