On Wednesday 12th December 2018, Liz and Alison presented a problem to classes around the world watching our live stream, and invited participants to send in their comments and solutions.
Here is the video (it is edited so that there is just a short gap between each section; pause the video for a few minutes if you would like to work on each part of the task!)
Once you've watched the video, you might like to take a look at Magic Crosses, and the solutions that were submitted by other people.