The geometry problems of finding rectangles that have numerically equal areas and perimeters knowing when the plane can be tessellated by congruent regular polygons are connected by the equation: m = 2n/(n-2). Three graphic approaches to the solution of the problem when m and n are integers are discussed. (MDH)

Presented is a method of reorganizing a high school geometry course to integrate coordinate geometry together with Euclidean geometry at an earlier stage in the course, thus enabling students to prove subsequent theorems from either perspective. Several examples contrasting different proofs from both perspectives are provided. (MDH)

Describes the habits of mind that would be most desirable for students to develop. In high school for example, content-specific habits would include geometric habits of mind that support the mathematical approaches, and algebraic ways of thinking that complement the geometric approaches. (AIM)

Presents a worksheet on graph paper that allows students to determine the perpendicular bisectors of given segments by folding the paper. Students then determine the slopes of the perpendicular bisectors and use inductive thinking to discover the relationship between the slopes of perpendicular lines. (MDH)

Explores the role that symbolic-graphical calculators can play in the current calls for reform in the mathematics curriculum. Discusses symbolic calculators and graphing calculators in relation to problem solving, computational skills, and mathematics instruction. (MDH)

The 1989 document, "Curriculum and Evaluation Standards for School Mathematics" provides a vision and a framework for revising and strengthening the K-12 mathematics curriculum in North American schools and for evaluating both the mathematics curriculum and students' progress. When completed, the Addenda Series is expected to consist of…