Rene Descartes lived from 1596 to 1650. His contributions to geometry are still remembered today in the terminology "Descartes' plane". This paper discusses a simple theorem of Descartes, which enables students to easily determine the number of vertices of almost every polyhedron. (Contains 1 table and 2 figures.)

This article discusses how paper folding can be used in the classroom to introduce the standard results of school geometry, such as the transversal and parallel lines results, along with results concerning angles in convex polygons and centres of triangles, for example. Angle bisectors, midpoints, perpendiculars are all straightforward…

Prediction is a great skill to have in any walk of life: it can, in fact, save lives at times. While the two investigations posed in this column may not be that dramatic, they might just increase one's appreciation of some important connections between grids and rectangles and the divisors of numbers that appear in the dimensions of those…

For over 30 years this author has been involved in the teaching and learning of mathematics and numeracy in Australian schools, teaching in high schools (Years 8-12) for more than 20 years at different school settings ranging from rural and remote to inner city, high socio-economic status schools to schools of students mostly from poorer, lower…

This article describes the Australian Informatics Competition (AIC), a non-programming competition aimed at identifying students with potential in programming and algorithmic design. It is the first step in identifying students to represent Australia at the International Olympiad in Informatics. The main aim of the AIC is to increase awareness of…

Imagine being able to engage students in learning statistics. Teachers would need their students to have access to a large database of real data, preferably about students. It would be even better if students were part of the database. Ideally, the data would enable students to ask questions of interest to them. For a teacher, it would be…

The Chinese tangram puzzle was known as far back as 1813. It has remained popular ever since. It consists of seven simple polygonal pieces of card which can be assembled in the form of a square. The reader is presented with some popular shape such as the man or cat above, and then asked to construct this using the tangram pieces. There are whole…

Reading in mathematics classrooms needs to be an active part of the learning process. If it continues to be viewed as a passive way to gain information, then its benefit to the learning process will also continue to be under-utilised. The "Read--Think--Do (x2)" model, designed by these authors and described in this article, can be a support to…

One of the most interesting and important proofs in the history of mathematics is the Pythagorean school's proof of the "irrationality" of the square root of 2. After a brief look at G. H. Hardy (1941) thoughts regarding it, two versions of the classic Pythagorean proof are examined and discussed in this article, one written by an American…

Traditionally, students learn arithmetic throughout their primary schooling, and this is seen as the ideal preparation for the learning of algebra in the junior secondary school. The four operations are taught and rehearsed in the early years and from this, it is assumed, "children will induce the fundamental structure of arithmetic" (Warren &…

According to this author, the solution to the "phonics versus whole language" debate over the teaching of reading is balance and a focus on the needs of all students. There is similarly a need, in developing numerate young people, to focus on the teaching and learning of mathematics and mathematics skills some of the time, and on application and…

If one rolls a coin across a chessboard and it comes to rest on the board, what is the probability that it covers some corner of one of the grid squares? The online magazine "Plus" (2004) posed this problem for students to solve. It is a useful problem for several reasons: it introduces the idea of probability in a continuous sample space, it has…

This article reports on the teaching of a unit of lessons which integrates mathematics with studies of society and the environment. The unit entitled "Population Growth Rates" was taught to a double class of Year 6 students by a team of three teachers. The objectives of the unit were: (1) to provide students with a real-world context in which to…

This article describes Cryptography, defined as the science of encrypting and deciphering messages written in secret codes, it has played a vital role in securing information since ancient times. There are several cryptographic techniques and many make extensive use of mathematics to secure information. The author discusses an activity built…

In this article, we report findings from a study in which the daily lives of novice and experienced secondary mathematics teachers in Victoria were tracked. Two novice and two experienced teachers were also interviewed. Data collection focused on the activities the teachers undertook in and out of working hours, and their reactions to them. The…