Hands-on math!

Intersection of two sets

The intersection of two sets are all the elements that appear in both sets.
For example, if you have the two sets of numbers: {3,4,5}, and {5,6,7}, the intersection of these sets is:{5} because only 5 appears in both sets. The symbol for intersection is an upside-down capital U, so if we call our first set "A" and our second set "B" then
A ∩ B = {5} .

You can think of the two sets as circles and the intersection of the two sets as the elements that are in the overlap area, like this:


<== because only 5 appears in both sets!
This kind of diagram, where the relationship of sets is shown as circles is called a Venn diagram

Now, here's a problem for you:

Set A: 5, 8, 3, 4, 5, 5, 9, 9
Set B: 3, 8, 8, 9, 3, 4, 0, 0

What is A ∩ B = {___, ____, ____, ____, _____, ____}
Hint: Circle the elements of B that you find also in A.