The Calculus of Friendship

The Calculus of Friendship was a very neat book.  It is a story of a math student and his high school teacher.  The student is a gifted math student who goes on to do great things in math.  He keeps in touch with his high school teacher by writing letters back and forth about interesting problems that they run into.  Then one day the student realizes that he never knew his long time friend in a personal way, and decides to go meet with him to have a real conversation about their lives.  This is a good book for high school calculus students to read becasue the caluclus that is presented in the book shows real world applications of calculus.