In the words of Robert McAfee Brown, "Storytelling is the most powerful way to put ideas into the world today." This book tells a story of the four basic number operations. The story personifies the operations as medical doctors: Dr. Addny Addition, Dr. Sidney Subtraction, Dr. Molly Multiplication and Dr. David Division. Each of the four doctors tells their story of when and how they operate on numbers through experiences of their own; listening to key words and phrases.