This problem scenario presents how a fifth-grade class used logical thinking and spatial reasoning to find the angle measurements of certain polygons without using a protractor. To access the full-size activity sheet, go to http://www.nctm.org/tcm, All Issues. Each month, this section of the Problem Solvers department showcases students' in-depth thinking and discusses the classroom results of using problems presented in previous issues of Teaching Children Mathematics.
Walter Stark, firstname.lastname@example.org, teaches fifthgrade mathematics at the Captain Vincent G. Fowler School PS 108Q in South Ozone Park, New York. He is interested in the strategies that students use to solve problems and how they apply their mathematical reasoning to their solutions.
Edited by Cathy Marks Krpan, email@example.com, a professor at the Ontario Institute for Studies in Education at the University of Toronto. She teaches math education courses in the Department of Curriculum and Teaching graduate program. Each month, this department showcases classroom results of using problems presented in previous issues of Teaching Children Mathematics.