Yogurt and her classmates are taking a break! The teacher brought in a lot of pizza earlier, so Yogurt is up to grab herself a slice. However, when she got up there, she noticed that half of all the pizzas brought in were already gone. She peeks over to the next pile to find it relatively untouched, and grabbed herself a slice. She ponders what kind of pizzas were in the empty boxes.
In a typical classroom, you often see certain foods go by first, with some foods often being left untouched. In this case, the meaty pizzas were the first to go, leaving Yogurt only the veggie pizzas to choose from.