Project Euler presents a series of mathematical and computer programming problems that will be a real challenge for any keen puzzle solvers out there! This is a great way to really stretch yourself beyond anything studied in the curriculum, and hopefully will “provide a platform for the inquiring mind to delve into unfamiliar areas and learn new concepts in a fun and recreational context” as you track your way through this massive project.
Project Euler can be quite challenging, so you might want to work through it with a teacher or in a small group.