Illustrates various methods to determine the perimeter and area of triangles and polygons formed on the geoboard. Methods utilize algebraic techniques, trigonometry, geometric theorems, and analytic geometry to solve problems and connect a variety of mathematical concepts. (MDH)

Presents methods for teaching two mathematical concepts that utilize visualization. The first illustrates a visual approach to developing the formula for the sum of the terms of an arithmetic sequence. The second develops the relationship between the slopes of perpendicular lines by performing a rotation of the coordinate axes and examining the…

Entering a value into a calculator and repeatedly performing a function f(x) on the calculator can lead to the solution of the equation f(x)=x. Explores the outcomes of performing this iterative process on the calculator. Discusses how patterns of the resulting sequences converge, diverge, become cyclic, or display chaotic behavior. (MDH)

Discusses the study of identification codes and check-digit schemes as a way to show students a practical application of mathematics and introduce them to coding theory. Examples include postal service money orders, parcel tracking numbers, ISBN codes, bank identification numbers, and UPC codes. (MKR)

Discusses the use of computers to teach proofs. Presents some possibilities of computer use in teaching proofs. (ASK)

Emphasizes the importance of proofs and offers examples and ideas that might help educators develop students' mathematical reasoning skills. (ASK)

Describes a game used in precalculus that builds interest and confidence in the uses of inverse functions. The game is preceded by a worksheet that enables students to discover that f(x) and f-1(x) are mirror images of the line y=x. (DDR)

Presents a project used to help students make connections between linear and exponential models and between arithmetic and geometric sequences. (KHR)

Presented is a lesson in which the patterns that occur within and between sequences of polygonal numbers present an opportunity for students to analyze, represent, and generalize relationships. Materials, objectives, levels, and directions for this activity are discussed. Worksheets to accompany the activities are provided. (CW)

Presented is a series of examples that illustrate a method of solving equations developed by Leonhard Euler based on an unsubstantiated assumption. The method integrates aspects of recursion relations and sequences of converging ratios and can be extended to polynomial equation with infinite exponents. (MDH)

Presents the use of spreadsheets as an alternative method for precalculus students to solve maximum or minimum problems involving surface area and volume. Concludes that students with less technical backgrounds can solve problems normally requiring calculus and suggests sources for additional problems. (MDH)

Stresses recognition and application of the identity property of 1 across the mathematics curriculum to help students overcome difficulties. (MKR)

Presents a brief definition and examples of residue designs while sharing some of the algebraic thought that a student used to form generalizations about the patterns discovered during the investigations of residue designs. (ASK)

Presents three teaching ideas: (1) investigating patterns in the sum of four numbers in a square array, no two from the same column or row; (2) using three-dimensional coordinates to generate models of three tetrahedra; and (3) applying the K=rs area formula for a triangle to other polygons. (MDH)

Demonstrates how graphing calculators can be used by students to solve equations involving absolute value. Allows students to make connections between the algebraic and graphical representations of the problem. (MDH)