Thoth Academy started in 2019 as a small collection of study notes for the students I was tutoring. It has since grown into a library of mathematics and physics material — notes, worked examples, and thousands of original practice problems.

• Study notes — concise summaries for topics from Algebra through Calculus, and from conceptual physics through AP Physics. Free, always.
• Practice problems with full solutions — worked step by step, so you can follow the reasoning rather than just check the answer.
• Test guides — what is actually on the SAT, ACT, AP, and SSAT, and how to prepare for each.
• Practice books — the complete problem sets, typeset and published.

Every problem in the practice sets is written from scratch and solved by hand before it is published. No recycled question banks, no scraped content. If a problem is here, it was built to teach one specific thing.

Questions, corrections, or suggestions are always welcome — joonho@joonho.net