There are 3 sets of courses of different difficulty and different sort of content. Click on "more about the..." button below to find more information about prerequisites and topics covered.
If you are not sure which course to apply for, the test below might help you make choice:
Take a course-suggestion test
Junior courses are aimed at those who have no or little experience in logical/olympiad-style problems. The courses cover many of the basic topics like two-person games, pigeonhole principle, standard combinatorics, colourings etc... Also there are a lot of problems where one needs to come up with a construction or algorithm. So whether you plan to focus on olympiads, computer science, or you simply want to try out some non-classroom maths, these courses are for you.
Intermediate courses are aimed at those who have about a year or two of experience in solving non-standard/olympiad-style mathematical problems. Knowing all the theorems/facts/ideas/... from Junior level course is a prerequisite. Moreover a big part of these courses are related to Number theory and Algebra therefore good algebraic skills are required as well. Note that some courses have a theme (e.g a course in geometry).
Senior courses are for experienced maths-problem-solvers and they last 12 weeks. So apply only if you are prepared to work hard :) The courses are no longer themed; instead they mimic olympiad-training programs given in many countries. Each contains a lot of advanced problems and a number of non-obvious theorems, with the teachers consider course-X as being really hard by any standard. The courses are most suitable for those who would like to take part in olympiads of serious level or explore hard maths. Apart from feeling comfortable with things covered in Junior&Intermediate courses, participants need to make sure they know enough of the relevant school material.