Lesson 90: Sets
Part 1
Objectives:
1. Students use set notation to indicate sets of numbers.
2. Students find the unions and intersections of sets.
3. Students determine whether a set is a subset of another set.
4. Students draw Venn diagrams to illustrate relationships among sets.
Definitions:
1. set: is a collection of elements
a. elements:
Example: The set of whole numbers can be represented as:
Notice the notation, list the elements of a set in braces {}
Why do we have ellipsis at the end, but not at the beginning?
Example: Use set notation to denote the set of integers.
Example: Use set notation to denote the set of even integers.
New Symbols:
 : indicates an element is in the set
 : indicates an element is not an element of the set
Example: Use set notation to indicate whether each number is an element of the set of
rational numbers.
1
a. 2
b.
c. 2
2
What other math symbol uses a slash mark to indicate the word not?
Example: Graph the elements of each set on a number line.
a. the set of integers
b. { 1, 2 , 3 , 4}