Play with our interactive machine and see if you can work out how to switch each light on. Is there a way to turn on all four lights at once?
Each number must be a factor or multiple of the last. What's the longest chain you can make?
Think of a two digit number, reverse the digits, and add the numbers together. Something special happens...
Watch this talk by Dr Vicky Neale as she explores some equations, and covers some highlights from the rich history of number theory along the way.