Presents activities related to some obscure tests for divisibility, which teachers may wish to develop as illustrative examples in the classroom, or as extension activities for groups of students. Begins with an exploration of divisibility by three, then discusses application of the technique to other numbers, and for numbers written in other…

Discussed is an approach in which algebra and geometry are interwoven in a series of problems that develop one from another. The two main concepts are the algebraic concept of function and the geometric concept of the "family of quadrilaterals." (MNS)

Proposes activities that promote students' awareness of the structure of the information involved in their everyday activities, and builds the concept of function from students' mental representations of phenomena. Recommends the use of spreadsheets to provide external representations of these functions. (DDR)

Discussed are the idea, examples, problems, and applications of convexity. Topics include historical examples, definitions, the John-Loewner ellipsoid, convex functions, polytopes, the algebraic operation of duality and addition, and topology of convex bodies. (KR)

Presents a series of challenges, problems, and examples to demonstrate the principle of mathematical induction and illustrate the many situations to which it can be applied. Applications relate to Fibonacci sequences, graph theory, and functions. (MDH)

Presented is a Poisson derivation using explicitly stated assumptions and exact functional equations. The assumptions are homogeneity, independence, and negligibility. Included are the derivations and proofs using L'Hopital's rule for each assumption. (KR)

Presents several problems that use calculator or computer-generated graphs of the absolute value function as related to the maximum and minimum functions to illustrate the statistical concepts of range, median, mean, and variance. (MDH)

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)

Proposes lessons for algebra students using the context of tax calculations to learn about the concepts of slope, split functions, averages, rates, marginal rates, and percents. Students explore ramifications of possible tax revisions. (MDH)

This empirical investigation, implemented with a computer program, examined the influence of graphical and numerical representations on the discovery process involving iteration sequence properties and concomitant problem-solving abilities for 79 eleventh grade students and 22 secondary mathematics teachers. Results indicate that heuristics and…

Presents sample lab activities in algebra for representing functions in concrete, tabular, graphic, algebraic, and word format. Activities described actively involve students in hands-on models. Problem-solving techniques and technology help to form algebraic-thinking skills. (AIM)

Included in this column are Star Trek, a geometric construction problem; a simplified approach to correlation using scattergrams; a calculus problem concerning second derivatives for extreme values; and a note on integration by parts. (MNS)

Reported is whether and how mathematics has changed during the 75 years of the Mathematical Association of America's (MAA) existence. The progress of mathematics is organized into 9 concepts, 2 explosions, and 11 developments. (KR)

College algebra is currently being taught using graphing calculators such as the TI-81. This document presents exploratory and problem solving activities that have resulted from classroom experiences with the TI-81. The activities have been designed to enhance the learning of some standard college algebra topics through the easy access to…

The quadratic function can be modeled in real life by a suspension bridge that supports a uniform weight. This activity uses concrete models and computer generated graphs to discover the mathematical model of the shape of the main cable of a suspension bridge. (MDH)