Lessons
A maths lesson, every couple of weeks.
Animated lessons for curious children and anyone preparing math contests. Each one is a tiny idea with surprising power: pigeonhole, parity, invariants, and the rest of the olympiad toolkit.
2 published. Watch the full playlist on YouTube or browse the @OlympiadHQ channel.
Core olympiad principles
The named ideas at the heart of olympiad-level reasoning. Each one is small enough to state in a sentence and powerful enough to settle dozens of problems.
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01 2:15 Pigeonhole Principle
If you have more pigeons than holes, at least one hole must contain two pigeons. A tiny idea, deadly when applied. We meet it through a sock drawer, thirteen children sharing twelve birthday months, and a beautiful olympiad problem about five points in a square.
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02 4:38 Parity
Even or odd: the simplest possible distinction. Yet it solves problems that look impossible. The mutilated chessboard, three glasses on a table, a knight that wants to travel from one corner to the other. We meet parity through three problems and learn to spot the parity move anywhere.