High school work

Bolded are handouts I think are especially good.

My materials

Properties of 2020: I scoured OEIS and compiled a list of properties of 2020. It's amusing but not very useful.
AIME Strategies: I compiled a list of strategies for the AIME.
Diagram Perturbation: Slick geometric transformation problems that feel like you’re building something on top of the existing figure.
Hidden Gems: Some problems that don’t get the love they deserve; many are taken from David Altizio’s collection.
Unorthodox Problems: A collection of fun problems.
Diophantine Equations: Some techniques to solve diophantines, like modular arithmetic, inequalities, etc.
Invariants: How to use quantities that don't change to solve problems.
Roots of Unity Filter: A neat algebraic trick with applications in combinatorics and number theory. Co-written with Raymond Feng.
LaTeX Basics: Fundamentals of LaTeX like common commands.

Over COVID, I wrote handouts with some of my friends, and a lot of people liked them! I especially recommend the polynomial/trig handouts.

One Page Summaries, me: A project to condense topics into one page each. Unfortunately, I never finished it.
Recursion, Jeff Chen: Intro to forming and solving recursions.
Modular Arithmetic, me: Intro to mods.
Sequence and Series, nikenissan: Intro to arithmetic, geometric, telescoping, and recursive sequences.
Polynomials, naman12 and me: Comprehensive guide to polynomials.
Trigonometry, naman12 and me: Comprehensive guide to trig techniques.
Group Theory, Emma Cardwell and Matthew Ho: Intro to group theory; I converted their class slides to notes.