The use of Adobe Flash© version 8 to design this site enhances your interactive experience. You can use your mouse or keyboard to move around the screens. Screen reader users should access content by selecting the 'text only' link.

If interactions run slowly on your machine you can adjust the quality to speed them up. To do this, open the game, then right click with your mouse over the screen, and select quality and low.

Some interactions have sound, so make sure you are switched on! To make any images bigger, right click and select Zoom in.

Select the web links and printable activity and information PDFs to take a deeper look at the maths behind the interactions. Or choose the video clips for a taster of the full lectures you can order on DVD. Transcripts of these lectures are also available through the onscreen links.