Peg and Cat Episode 13 The Birthday Cake Problem / The Doohickey Problem Episode Title:The Birthday Cake Problem / The Doohickey Problem.Episode Description: The Birthday Cake Problem Peg and Cat make a rockin' birthday cake for Jonah and his friends the Teens, but they need to figure out how old he is turning first. Primary Learning Goal: The teen numbers. / The Doohickey Problem When their space ship is smashed, Peg and Cat must reassemble its variously shaped parts, and retrieve sixteen stolen doohickeys. Primary Learning Goal: Patterns. Secondary Learning Goal: Shapes, the number 16.