Lesson objective: Understand that the probability of a compound event is the fraction that represents the number of favorable outcomes of the total number of possible outcomes.

Students bring prior knowledge of probability of simple events from 7.SP.5. This prior knowledge is extended to compound events as students find probabilities of two or more events occurring at the same time. A conceptual challenge students may encounter is understanding that when two or more events occur at the same time, the probability of each event must be multiplied, not added.

The concept is developed through work with tables (area model) and tree diagrams which help students understand that the probabilities of two or more events are multiplied to find the probability of both occurring together.

This work helps students deepen their understanding of operations because the probability of a compound event is the ratio of the number of favorable outcomes to the total number of possible outcomes.

Students engage in Mathematical Practice 5 (using appropriate tools strategically) as they use tables and tree diagrams to find the probability of compound events.

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