This paper explores a geometrical way to sketch graphs of the general quadratic in two variables with Geometer's Sketchpad. To do this, a geometric procedure as described by De Temple is used, bearing in mind that this general quadratic equation (1) represents all the possible conics (conics sections), and the fact that five points (no three of…

At first geometry was a practical subject to be used in the physical world. Then it took on another role as a system of thought and it became geometry for the mind. This issue's "scrapbook" consists mainly of interesting anecdotes related to geometry.

Describes levels of thinking in geometry defined by Pierre van Hiele and Dina van Hiele-Geldof and discusses recent research on geometry learning levels among sixth and ninth graders. (GC)

This model is useful in identifying specific learning problems and in providing techniques for the teacher to motivate and teach students at all levels. What it is and how it can be used are discussed, illustrated by specific strategies for geometry and science. (MNS)

Argues that proving something begins with an assumption and proceeds logically to a conclusion, thus convincing by offering arguments. Describes some pitfalls involved in proving through examining several case histories. Offers suggestions for teaching the proof process. For example, sometimes an extreme example or counterexample will do more to…

Explores the role of proof in mathematics education and provides justification for its importance in the curriculum. Discusses three applications of dynamic geometry software--heuristics, exploration, and visualization--as tools in the teaching of proof and as potential challenges to the importance of proof. (Author/MM)

Features articles about physical therapy and its history as related to geometry through measurement of body angles. Includes open-ended worksheets for mathematics activities that introduce students to angle measurement, data analysis, and mathematical tools. Activities include: (1) Making Your Own Goniometer; (2) Range of Motion; (3) Active versus…

Beginning geometry students misunderstand the requirements of formal proof because of confusion between deductive reasoning and argumentation. Presented is a cognitive analysis of deductive organization versus argumentative organization of reasoning and the applications of this analysis to learning. Implications of a study analyzing students'…

The purpose of this paper is to identify how the theory and techniques of research in cognitive development can be applied to the study of learning and instruction in mathematics. Five basic research paradigms are characterized; major directions of research on number, measurement, geometry, and adolescent reasoning are identified. Most of the…

The purpose of this report is twofold. The first is to deliver an accurate portrayal of students' achievement in geometry and measurement as gleaned from the results of the 1986 Massachusetts Educational Assessment Program (MEAP). The second is to provide K-12 teachers of mathematics with activities that have proven to be helpful in encouraging…