Some people became mathematics or science teachers by default. There was once such a limited range of subjects that students who could not write essays did mathematics and science. Computers changed that. Word processor software helped some people overcome huge spelling and grammar hurdles and made it easy to edit and manipulate text. Would-be…

The early eighties saw a period of rapid change in computing and teachers lost control of how they used computers in their classrooms. Software companies produced computer tools that looked so good that teachers forgot about writing their own classroom materials and happily purchased software--that offered much more than teachers needed--from…

This is the first of two articles which describe how to use "JavaSketchPad" to explore the centres of a triangle. This introductory exercise is suggested in the GSP "Workshop Guide". Students can use "JavaSketchPad Interactive Geometry" (JSP) at home at no cost. They are likely to impress their parents with their enthusiasm for geometry and all…

Tangrams have sometimes been used as an extension activity intended only to keep faster students busy while others finished essential desk-work. Without adequate introduction, many find that tangrams are just an open-ended form of a jigsaw puzzle. Happily teachers have discovered that games provide an effective introduction to a new topic. In the…

Parabolic shapes are easy to find. Many homes outside the cable area have parabolic antennas to receive television transmissions from a satellite far out in space. Parabolic extrusions are used as reflectors behind fluorescent tubes and solar heated water pipes. Parabolic reflectors are used to build solar ovens, searchlights and radio telescopes.…

In a previous article in this journal, simple constructions were considered to study the reflective property of a parabola and of a paraboloid. The purpose was to help middle school students understand the importance of the parabola shape and its ability to focus parallel rays. The examples demonstrated a use of the two "Cabri" products to study a…

When the author first used "VisiCalc," the author thought it a very useful tool when he had the formulas. But how could he design a spreadsheet if there was no known formula for the quantities he was trying to predict? A few months later, the author relates he learned to use multiple linear regression software and suddenly it all clicked into…

In 1854 the German scientist Zeising claimed that the ratio of a person's height to the height of their navel is in the same ratio as the Golden Ratio ([phi] = 1.62). There is so much hype about the Golden Ratio that it is worth reading an article at http://www.maa.org/devlin/devlin_06_04.html. It explains why some of the more far-fetched ideas…

In the Western Gregorian Calendar, the date of Easter Sunday is defined as the Sunday following the ecclesiastical Full Moon that falls on or next after March 21. While the pattern of dates so defined usually repeats each 19 years, there is a 0.08 day difference between the cycles. More accurately, the system has a period of 70 499 183 lunations…

The transfer of data from one part of a computer to another has always been a complex task in which speed is traded against accuracy and the time required for error correction. Much more complex therefore is the transfer of information from one machine to another of a different type. Difficulties arise when machines are updated, when file formats…

The Golden Ratio is sometimes called the "Golden Section" or the "Divine Proportion", in which three points: A, B, and C, divide a line in this proportion if AC/AB = AB/BC. "Donald in Mathmagicland" includes a section about the Golden Ratio and the ratios within a five-pointed star or pentagram. This article presents two computing exercises that…

In early 2004, Cabrilog released version "II plus" of their interactive geometry package. According to the author, "Cabri Geometry II plus" is clearly a much more useful package than the earlier version. However, unlike other sophisticated applications packages, the designers have avoided creating so many options that secondary students lose their…

Presents an example of an introductory lesson on spreadsheets which provides a quick overview/revision of the essential elements of spreadsheeting before progressing to programmed exercises. (ASK)

Presents an activity in which students use computer-based spreadsheets to find out how much grain should be added to a chess board when a grain of rice is put on the first square, the amount is doubled for the next square, and the chess board is covered. (ASK)

Utilizes LOGO to teach the concept of inequalities by programing the turtle to take random walks in the coordinate plane restricted to predetermined regions defined by inequalities. The students task is to discover the inequalities that define the illegal areas into which the turtle must not move. Provides examples and corresponding computer…