The current popularity of the Harry Potter books (Rowling 1998, 1999a, 1999b, 2000, 2003) gives teachers a new and unique opportunity to integrate literature with mathematics. Often, books that are connected to mathematical explorations are picture books, which teachers can read easily in one sitting to a group of children. The books in the Harry Potter series are chapter books, which teachers must read to students over a period of several weeks. Despite the time investment, however, the appeal of the Harry Potter books to readers of all ages makes them ripe for a connection to mathematics.