A process for eliminating the xy term in a quadratic equation in two variables is presented. The author feels this process will be within the reach of more high school students than more commonly used methods. (MK)

The article presents a general test for divisibility that includes composite numbers and shows that such a test can be used to determine divisibility by several numbers simultaneously. (MK)

An algorithm for multiplying natural numbers is described. The algorithm provides a chance for some unusual drill and might serve as an enrichment topic. (MK)

Activities to be used before teaching the Pythagorean Theorem are described. Sample worksheets are provided. (MK)

A 20-question quiz on the uses of numbers in the real world is presented. (MK)

This discussion of ways to use spirolaterals in the classroom includes making conjectures, hypotheses testing, and proofs, as well as a number of examples. (MP)

A systematic search is given for products where reversing the digits does not change the answer. Related questions are suggested that can be solved by the same discovery approach. (MP)

The use of a multiple approach using both geometric and algebraic contexts is suggested in teaching concepts. Several examples are given including area and multiplication, length and number, and functions and power. (MP)

The use of the Mira, a geometric device for studying reflections, is discussed. Proved are that all Euclidean constructions can be made with a Mira and that the Mira can be used to trisect an angle. (DT)

A cake recipe is given in terms of calculus problems, where the solution to the problem tells the amount of ingredients to be used. (DT)

A course for high school students who have completed one semester of geometry explores neutral geometry (no parallel postulate), Lobachevskian, and Riemannian geometries. The teachers believe that students who study several postulational systems gain a better understanding of Euclidean geometry. (SD)

Presents a Monte Carlo simulation on probability using a telephone directory as a pseudorandom-number generator. Claims that Monte Carlo simulations offer a way to teach probability concretely and with understanding and that students enjoy the probability experiments. (ASK)

Presents an activity to teach piecewise functions using wax paper and rectangular grids. Helps students understand the idea of different pieces by literally "piecing" together a new type of mathematical function. Also describes a followup activity and explains how piecewise functions can be graphed using graphing calculators. (NB)

Presents new proofs of the Pythagorean theorem while exploring examination questions. Briefly reviews the work of Elisha Scott Loomis, a mathematician who amassed 320 different proofs of the theorem. (DDR)

Presents an activity to involve students in mathematical communication and creative thinking. The activity is similar to the "pass it along" gossip game in which each person in a chain adds a piece of information. The class analyzes the resulting mathematics problem using George Polya's problem-solving techniques. (MKR)