Presents an investigation that guides students in detecting vertical and horizontal lines of symmetry as well as rotational symmetry in the decorative designs of wrought-iron doors. (ASK)

Presents a class project for creating a time line depicting the history of geometry that includes writing short biographies of mathematicians and summarizing geometric ideas to form an historical perspective. (ASK)

Presents a mathematical puzzle that asks about "missing" area and leads to an exploration of the Fibonacci sequence as well as genuine inquiry in plane geometry connected to algebra. Discusses the inquiry, the concepts, the solution, and an extension that deepens all students' understanding of the connections between algebra and…

Presents an activity in which students use mathematical thinking and applications to analyze Major League Baseball home run data. (ASK)

Presents a hands-on modeling experiment that focuses on hyperbolic functions, asymptotes, data analysis, applied statistics, and optimization problems. (ASK)

Presents activities that allow primary grade students to develop specific thinking strategies for basic facts such as counting on, using doubles, and making 10 in problem-solving settings. Discusses other topics such as probability, spatial sense, and money. Offers rich opportunities for reasoning and communication. (ASK)

Demonstrates that the equation of a circle (x-h)2 + (y-k)2 = r2 with center (h; k) and radius r reduces to a quadratic equation x2-2xh + (h2 + k2 -r2) = O at the intersection with the x-axis. Illustrates how to determine the center of a circle as well as a point on a circle. (Author/ASK)

Presents a project that asks students to relate mathematical operations to real-world situations, communicate mathematical concepts in writing, share their ideas with their peers, and exercise their creativity. (ASK)

Discusses students' progress through distinct levels in the development of their thinking as described by van Hiele levels. Focuses on the quadrilaterals and suggests some level 3 tasks and construction problems. (ASK)

Describes an experiment with two participants, one of which is familiar with the Geometer's Sketchpad but not with Cabri-Geometre and vice versa. Displays the work of both participants when they are given two geometry problems in secret and 20 minutes to work on each, the first with software that they are familiar with and the second using the…

All teachers face the dilemma of trying to cater to the range of abilities of the children in their classes. Explains one teacher's attempt to accomplish this. (ASK)

Reviews some fundamental mathematical ideas on sets and counting. Provides problems based on those ideas and their answers. (ASK)

Presents two activities on addition, one for classifying and one for symmetry. (ASK)

Examines the role of variation in statistics education. Describes a chance and data unit with a focus on variation that was conducted in three high school mathematics classes. (ASK)

Presents two problems whose solutions can be enhanced using the Geometer's Sketchpad to solve the problems. Concludes that available computer technology can aid in the analysis and solution of some interesting geometry problems. (ASK)