Students learn how to find the union and intersection of elements using basic set notation. As learning progresses students consider the complement of a set while reviewing basic number properties.

At the start of the lesson students recap using sample space diagrams to find the probability of cracking a code. The plenary is used to assess progress against the differentiated learning objective through a typical exam question.

**Differentiated Learning Objectives**

- All students should be able to list the elements of a set.
- Most students should be able to enumerate sets and unions/intersections of sets systematically.
- Some students should be able to find the complement of a set.