The importance of visualisation and multiple representations in mathematics has been stressed, especially in a context of problem solving. Hanna and Sidoli comment that "Diagrams and other visual representations have long been welcomed as heuristic accompaniments to proof, where they not only facilitate the understanding of theorems and their…

This article presents the authors' personal accounts and their experiences in working on mathematics using "arms." "Arms" is an idea that first appeared as a program written by John Warwick and David Wooldridge in an ATM publication "Some Lessons in Mathematics with a Microcomputer," 1983. The introduction to…

The author first saw Trevor Fletcher's film on the cardioid as an undergraduate in 1959. When he saw Fletcher's cardioid film once again, the author was vividly reminded of his first experiences of animated mathematics nearly 50 years before. He discovered that the idea of using mental pictures to develop dynamic images came from work by the Swiss…

When the author started his visualization session at Brampton by showing a still from Kate Mackrell's "Kaleidoscope," he was immediately struck by one student's description of a symmetry and reflection line that was quite at odds with what he was holding. Since he had seen the whole thing moving on a number of occasions, the author was hanging on…

As a result of attending a course on moving images, the authors consider the balance between visualising and verbalising geometry. In thinking about the balance between visualising and verbalising (and verbal reasoning), the authors began to appreciate more than before that geometric visualisation is greatly aided by what they know--if everyone…

As well as being important for school mathematics, spatial thinking is a big component of advanced mathematical studies too. As Jones (2001:55) points out, "Much of the thinking that is required in higher mathematics is spatial in nature. Einstein's comments on thinking in images are well known. Numerous mathematicians report using spatial…

With both "Cabri" and "Autograph" now venturing into 3D, the dimension that previously was only demonstrated in the classroom with a lot of arm waving and crude wire cages can now be explored dynamically on screen. "Cabri 3D" concentrates on constructions, using the principles of Euclidian geometry, whereas "Autograph" creates objects using a…

The author describes a pilot study to investigate the extent to which learners use imagery in a variety of spatial problems. In order to discover how to encourage pupils to use imagery and thus to become better problem solvers, this study set out firstly to explore how pupils are able to use imagery in a variety of tasks. The tasks involved mental…