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 Sunday, 6th of February.
You may notice some problems are missing... I'm still migrating articles from my old blog.
Pega numa folha de papel e num lápis. Agora vou pedir-te que escrevas umas letras na folha e depois vou desafiar-te a dobrar a folha... Soa fácil? Prometo que não vai ser.