This column solicits mistakes, fallacies, anomalies, et cetera, that raise interesting mathematical issues and may prove useful to teachers. Included in this issue are yet another proof that zero equals one and a differentiation that yields three equals two. (Author/JJK)

A method of using vector analysis is presented that is an application of calculus that helps to find the best angle for tacking a boat into the wind. While the discussion is theoretical, it is seen as a good illustration of mathematical investigation of a given situation. (MP)

A method for finding the complex roots of a graph is detailed. A conjecture is made regarding the nature of zero points of fourth-degree polynomial functions, but it is not proven in general. Mathematical induction is viewed as a promising tool to prove the conjecture that turned out unproductive. (MP)

The material attempts to find the maximum number of non-congruent figures that can be generated from a nine-pin geoboard, and considers the maximum number of figures possible on boards of any size. The exploration starts by grouping sets of pin patterns into groups of equivalent classes. (MP)

Describes a program written in BASIC, called BIGNUM, that was designed to aid in handling big numbers. The program adds, subtracts, multiplies, divides, and raises to a power integers of up to 1024 decimal digits and is thought to be usable on many types of machines. (MP)

A history of perfect numbers is presented, which briefly covers the 27 values known at this time. (MP)

This activity guide is a supplement to the November 1996 issue of the National Council of Teachers of Mathematics Student Math Notes. It contains a series of problems based on one main story problem. Using this problem and the other problems contained in the guide based on it, students explore different mathematical concepts such as graph theory,…

The evolution of Archimedes' method is traced from its geometrical beginning as a means to approximate pi to its modern version as an analytical technique for evaluating inverse circular and hyperbolic functions. It is felt the web of old and new algorithms provides considerable instructional material, and ideas are offered. (MP)

Problems with apportioning seats within the House of Representatives every 10 years are discussed. The history of the problem and the nature of the politics involved are reviewed, and the current method in use is detailed along with its flaws. A call for a more sensible system is made. (MP)

A new approach to classifying quadrilaterals is presented that tries to classify all possible combinations of shapes and angles by removing the traditional Euclidean viewpoints. The document concludes with a brief look at other types of polygons. (MP)

This workbook is designed to be used as a review at the end of a college level course in algebra and trigonometry. Four review sheets containing 117 problems provide hints and detailed solutions for each problem. (YP)

Presents a variety of mathematics activities for students to solve. Sections are included on geometrical dissection, prime numbers, trigonometry, and number concepts. (RH)

A problem in applied mathematics is presented that is thought fit for a study project by secondary students. The analysis includes topics in beginning algebra, theory of interest, and theory of sums of series of infinite length and looks at trade-offs between price and mileage. (MP)

The problem deals with calculating the probability that two or more students in a given class have the same birthday. A sample of an experiment that can be carried out by hand in a class is first noted. A program written in BASIC and a sample run is then presented. (MP)

Several subtraction algorithms are analyzed to see if they involve borrowing. The main focus is on an analysis of a procedure called the residue method. The operational arithmetic which underlies the symbolic manipulations is examined and conditions where the method does and does not use borrowing are highlighted. (MP)