In this article, we discuss a popular puzzle we have used numerous times with our preservice elementary and secondary mathematics teachers. Students find the puzzle engaging; its primary appeal to us lies in the mathematics behind it.
Tod Shockey, email@example.com, is an assistant professor in the department of mathematics and statistics at the University of Maine, Orono, ME 04469. He is interested in ethnomathematics.
David Bradley, firstname.lastname@example.org, is an associate professor in the department of mathematics and statistics at the University of Maine. He is a research mathematician working in number theory and special functions.