John W. Lawrence is Professor Emeritus at the University of Waterloo. He was born in Ottawa, Canada, and received degrees from Carleton University and McGill University. After a year of postdoctoral work at the University of Chicago, he joined the Pure Mathematics Department of the University of Waterloo. He now lives with his wife Louise, in Thornhill Canada, where he continues his research in mathematics and probability. Frank A. Zorzitto is Professor Emeritus at the University of Waterloo. After receiving his doctorate at Queen's University in Kingston, Canada, he served for forty years as a researcher in algebra and a professor in the Pure Mathematics Department at the University of Waterloo, and served as Department Chair for twelve years. In recognition of his commitment to the education of students, he received the University's Distinguished Teaching Award. Upon his retirement he was made an Honorary Member of the University. Currently he offers an online course to high school math teachers, based on his e-book A Taste of Number Theory. He continues to teach and to write in his retirement.