When the beloved teacher Mrs. Langley leaves to have a baby, the kids get a long-term substitute, Mr. Shue. Mr. Shue seems much more serious and not nearly as much fun as Mrs. Langley, so the kids decide they have to win him over. The only problem is, he only seems to like one thing - math. With the help of Celia Lopez, Gus the baker's niece, they eventually succeed, and in the process learn that sometimes you need to give people a chance.