Cardinality is the count of numbers in a set or the last number you say when counting. Numbers such as 1, 2, 3, and 4 are cardinal, or counting numbers. Numbers such as first, second, third, and fourth are ordinal, or positional, numbers. The goal here is to have students understand the relationship between numbers and quantities and connect counting to cardinality or the number in a set. They need to realize that the last number name said tells the number of objects counted and that the number of items is the same regardless of their arrangement or the order in which they were counted. The video is an example of a boy who has not developed cardinality yet. The video help people understand cardinality, plus it's super cute.