Blog posts with problems to get your brain going! You get a new problem every fortnight and the solutions are published later.
If you want the problems delivered to your inbox be sure to subscribe to the Problems newsletter.
The next problem is scheduled for late June.
You may notice some problems are missing... I'm still migrating articles from my old blog.
Take out a piece of paper and a pencil, I am going to ask you to write some letters in your sheet of paper and then I am going to challenge you to fold the sheet of paper... with a twist!