This book introduces concepts of geometry that students use throughout middle-grade and higher-level mathematics courses. These concepts, presented through the study of transformations, provide a framework for other important topics such as number, measurement, proportional reasoning, and graphing on the coordinate plane. The book is designed for…

Presents new proofs of the Pythagorean theorem while exploring examination questions. Briefly reviews the work of Elisha Scott Loomis, a mathematician who amassed 320 different proofs of the theorem. (DDR)

Shows how the phenomenon of instability in the solution of a system of linear equations can be analyzed both algebraically and geometrically. (KHR)

Introduces a special triangle for which many different problems can be posed on the basis of one unusual property. Presents three problems and considers different approaches for the first problem. Explores other mathematical problems using the "What if not?" strategy that can be used as classroom activities. (KHR)

Comments on student responses to the three dimensional items produced by first investigating flat paper cutouts of the items. (KHR)

Discusses examples of the detailed explanations that students offered in response to a written, open-ended geometry task, especially the ways in which students communicated their knowledge. Illustrates how different students may select different methods of communication such as using text, diagrams, or mathematical symbols to display their…

Describes an activity in which students observe a simple situation, explore conjectures, and generate conclusions from their exploration of the conjectures to develop the essential triangle-congruence theorems. Includes teacher's guide. (KHR)

Examples and solutions to these problems are presented. Figures for which different equations are necessary are presented. The use of the geoboard for this exploration is emphasized. (CW)

Presents a teaching experience with high school students in geometry class using hand signals that reinforce meaning of geometric concepts. (KHR)

Describes ways of using existing popular songs, writing raps, or writing new words for existing tunes in the mathematics classroom to supply motivation and mnemonics. (KHR)

The experiences of elementary teachers who invited their students to verify geometric theorems prior to the introduction of protractors form the basis of a pedagogical strategy for a sequence of learning activities offered here. Discussion focuses on the students learning strategies about angle concepts utilizing the dynamic interpretation of a…

This book offers ideas to enrich instruction and help teachers explore the intrinsic beauty of math. Through dozens of examples from arithmetic, algebra, geometry, and probability, the symmetries, patterns, processes, paradoxes, and surprises that have facilitated generations of great thinkers are revealed. Activities include: (1) The Beauty in…

This guidebook is designed to assist teachers and other local school district personnel in the planning and the teaching of the high school geometry course, with essential elements as mandated by the Texas State Board of Education in 1989. Research on student learning in geometry provides the logical rationale for the instructional sequencing and…

Offers a problem for teachers to try with their students. The problem is presented visually as a row of 15 connected squares and the task is to determine the number of rectangles. The goal is to encourage teachers to reflect on students' work and analyze classroom dialogue. (PVD)

Discusses etymologies of mathematics words as a rich resource for deepening student understanding and appreciation of mathematics, history, and language. Presents detailed examples concerning the branches of mathematics, conic sections, and words of Arabic origin. (KHR)