The document is a letter from a mathematics department recommending a student take AP Computer Science based on their success in math. It describes AP Computer Science as a full-year honors course covering topics equivalent to half a college computer science major, using the Java programming language. It lists many topics that will be explored, including computer literacy, programming structures, algorithms, data structures, and applications like simulations, graphics and encryption. It encourages the student to consider taking AP Computer Science as their math-related skills will help them succeed in learning programming concepts.