Practice
Built alongside the chaptersPractice collects everything you answer outside the reading: the review queue, mixed sets, drills, chapter tests and the problem bank.
Until it is built, the exercises and olympiad problems are inside each section, and every miss is already recorded in your error log.
What this part of the site will hold
- Review queue: missed questions and key formulas come back after 1, 3, 7 and 14 days, about ten minutes a day.
- Mixed sets from the first week, with the topic hidden, because spotting which idea a problem needs is the real skill.
- Drills: mental arithmetic, orders of magnitude, units, formula recall and spherical triangles.
- Chapter tests of ten questions, unlocked when a chapter is finished.
- The problem bank: past IOAA theory and data-analysis problems restated in our own words, with step-by-step solutions revealed one step at a time and filters by chapter, year, round and level.