“Delving Deeper” offers a forum for classroom teachers to share the mathematics from their own work with the journal's readership; it appears in every issue of Mathematics Teacher. Manuscripts for the department should be submitted via http://mt.msubmit.net. For more background information on the department and guidelines for submitting a manuscript, visit http://www.nctm.org/publications/content.aspx?id=10440#delving.
Roger D. Cox, firstname.lastname@example.org, has taught high school mathematics for thirty-five years, including nineteen years at Taipei American School in Taiwan. He enjoys building model ships, fly fishing, and working on challenging problems that often arise from student questions. Susan Cox