Describes a number sequence made by counting the occurrence of each digit from 9 to 0, catenating this count with the digit, and joining these numeric strings to form a new term. Presents a computer-aided proof and an analytic proof of the sequence; compares these two methods of proof. (YP)

This article develops an algorithm to find all solutions to the problem, making all sums of a hexagram's nine lines the same. It shows how to exploit the geometric structure of the hexagram and its group of automorphisms. (YP)

Described are several programs that enable the user to evaluate derivatives to order n of any elementary function by using the combination of automatic differentiation method and A Programming Language (APL). Programs calculating first- and higher-order derivatives are presented. Selected APL symbols are appended. (YP)

This is a collection of Pascal programs that were developed for a 1986 National Science Foundation-sponsored high school teachers' summer workshop. The programs can be used as a means of extending or enriching textbook material in either high school mathematics or Pascal courses. Some suggested uses are: (1) teacher demonstrations in mathematics…

This paper provides an historical perspective on the possible roles of cognitive technologies in thinking as "reorganizers" of the mind. It suggests that by understanding the transformational roles of advanced technologies for mathematical thinking, positive contributions can be made to research and practice on the use of computers in…

Describes the Plane Geometry System computer software developed at the Educational Computer Systems laboratory in Sofia, Bulgaria. The system enables students to use the concept of "algorithm" to correspond to the process of "deductive proof" in the development of plane geometry. Provides an example of the software's capability…