Two statements concerning magic squares, considered as 3x3 matrices, are discussed and their proofs given using only high school level techniques. (MP)

Included in this section are brief articles on drawing altitudes of triangles, sketching parabolas, and visualizing variability. (MNS)

Introduces concepts of modern algebraic group theory in the form of a game. Peg boards and rubber bands represent nonnumerical group elements and are manipulated under the operation of reorienting a regular polygon. Symmetry groups are used to explore set properties, as well as commutative and noncommutative operations. (CMS)

This puzzles uses a crossword format with the entries being factors of given polynomials. (MP)

Practical decisions involving fuel economy are shown to require important skills from secondary school algebra and analysis. (MP)

The topics of angle construction, angle trisection, and regular polygon construction with only a straightedge and compass are discussed for angles with integer measure. (MP)

An investigation of these numbers is shown to give students an opportunity to make use of such mathematical skills as algebraic substitution, modular arithmetic, counting arguments, and mathematical induction. (MP)

An example is given of a class of problems whose solutions require the use of a scientific calculator in order to plot the graphs. (MP)

Using sequential chains of regular n-gons in a row with one side touching, as for example, one triangle, two triangles, three triangles, and so on, students graph the length of the perimeter versus the number of n-gons and determine the functional relationship for different values of n. (MKR)

Discusses: (1) use of matrix techniques to write secret codes (includes ready-to-duplicate worksheets); (2) a method of multiplication and division of polynomials in one variable that is not tedius, time-consuming, or dependent on guesswork; and (3) adding and subtracting rational expressions and solving rational equations. (JN)

A paper staircase drawn on a grid forms the basis for a discovery lesson in algebra. (DT)

Presents a strategy for graphing conic sections on the polar plane without using a table of values by beginning with information gained from the graphs of circular functions. (MKR)

Some properties of perfect numbers are illustrated. (SD)

The author describes a series of current economic ideas and situations which can be used in the mathematics classroom to illustrate the use of signed numbers, the coordinate system, univariate and multivariate functions, linear programing, and variation. (SD)

Allowing students to discover a winning strategy for this game is suggested as a way to introduce modular arithmetic. (MP)