BJ and Riff find a pirate map, but in order to find the treasure, they have to be able to count. Since Baby Bop has not learned to count yet, Barney offers to help teach her so she can participate. And Baby Bop discovers the greatest treasure in the world. Then it's time for a music concert in the park. As Riff works on his "one-man band," the others make posters for the show.