The first part of an investigation into how to represent numbers using geometric transformations that ultimately leads us to discover numbers not on the number line.

Introduces the idea of a twizzle to represent number and asks how one can use this representation to add and subtract geometrically.

Using balancing scales what is the least number of weights needed to weigh all integer masses from 1 to 1000? Placing some of the weights in the same pan as the object how many are needed?

A loopy exploration of z^2+1=0 (z squared plus one) with an eye on winding numbers. Try not to get dizzy!

Make the twizzle twist on its spot and so work out the hidden link.

This article for the young and old talks about the origins of our number system and the important role zero has to play in it.

This article looks at how models support mathematical thinking about numbers and the number system

Where we follow twizzles to places that no number has been before.

Have you seen this way of doing multiplication ?