Have you seen this way of doing multiplication ?
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?
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
Arrow arithmetic, but with a twist.
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.
Make the twizzle twist on its spot and so work out the hidden link.
A loopy exploration of z^2+1=0 (z squared plus one) with an eye on
winding numbers. Try not to get dizzy!
How can you use twizzles to multiply and divide?
Where we follow twizzles to places that no number has been before.
Can you explain how Galley Division works?
First or two articles about Fibonacci, written for students.