There are 5 alligators, each with a group of 4 legs.

To find out that 5 alligators have 20 legs we can add using repeated addition.

4 + 4 + 4 + 4 + 4 = 20

We can also multiply to find the number of legs that 5 alligators have.

5 groups of 4 legs
5 x 4 = 20