Describes the process of combining two theorems from plane geometry to form the chord-line theorem. In this theorem, the concept of two intersecting chords or extended chords is replaced by a single chord-line. (DDR)

Discusses some of the challenges faced by blind and visually impaired students, and some of the tools available to help these students in their efforts to learn mathematics. Argues that much of the language of mathematics relies heavily on visual reference. (DDR)

Describes activities that use geoboards to explore properties of polygons such as the relationship between a polygon's number of sides and the sum of its interior angles. Describes a generalized method for constructing any Pythagorean triangle. (DDR)

Describes the results of a teacher's exploration of the effects of using graphing calculators in calculus instruction in sections other than those that are experimental. Two experimental and two traditional sections of Calculus I and II participated in the study. (DDR)

Describes activities in which students perform experiments with physical models that they create. Students develop geometric intuition and build a concrete foundation upon which abstract principles can be built. (DDR)

Provides activities that deal with Fibonacci-like sequences and guide students' thinking as they explore mathematical induction. Investigation leads to a discovery of an interesting relation that involves all Fibonacci-like sequences. (DDR)

Presents a scenario in which two people solve a programming problem by discussing various number sequences and functions. The problem is redefined as one related to number theory and operations research. (DDR)

Presents an approach to explaining a relation, a - b = -(b - a), that is difficult for algebra students to understand. The approach came about as a result of discussions with students in which they provided many novel explanations. (DDR)

Presents two real world applications that use derivatives and are related to computing the distance required to stop an airplane. Examines the curve-fitting techniques used to develop an equation for braking force and develops equations for the deceleration and speed. (DDR)

Presents strategies that utilize graphing calculators and computer software to help students understand the concept of minimizing the squared residuals to find the line of best fit. Includes directions for least-squares drawings using a variety of technologies. (DDR)

Presents an activity that establishes a graphical foundation for parametric equations by using a graphing output form called tubeplots from the computer program Maple. Provides a comprehensive review and exploration of many previously learned topics. (ASK)

Discusses how students fail to recognize the underlying equivalence when the same set of points is represented by a graph or an equation or a table. Presents activities in which more than one form of representations of the same information are included. (ASK)

Describes desktop teaching which involves giving students individual topics and having them prepare lessons on those topics to share with the class. Presents the structure of desktop teaching including how to prepare, introduce, set up, implement, and evaluate it. Emphasizes that desktop teaching helps students engage in discussing and learning…

Presents an assignment given to students to produce a report on perfect numbers and their properties. Summarizes the history of perfect numbers and their features. Recommends spreadsheet, theoretical, and programming activities on perfect numbers. (ASK)

Presents an activity on the sum of the measures of the interior angles of a five-pointed star by using The Geometer's Sketchpad. (ASK)