For the past 26 years, William has taught mathematics to students from ages eleven to eighteen in public and private schools in Europe, Asia, Australia, and the United States. Originally from Maine, William is a Williams College graduate and was honored with the 2013 Presidential Award for Excellence in Mathematics and Science Teaching. He has served as Deputy Chief Examiner with the International Baccalaureate, responsible for writing examination papers, leading marking teams, and setting score boundaries. He is currently the Mathematics Department Chair at Proctor Academy in Andover, New Hampshire. When not playing with mathematics, William might be out on his bike, traveling, or spending time with his lovely wife Lindsay and their children Gabriel, Gypsy, Lucy, Phoenix, Zoe, Rose, and Julian.