7 tracks, one growing library.
Start with the track you recognise. New notes settle into the right place as the library grows.
A-Level Maths
Pure, Mechanics and Statistics — written alongside Edexcel and AQA specs.
IGCSE Maths
Cambridge & Edexcel IGCSE — core and extended, topic by topic.
AP Calculus & Stats
AP Calc AB/BC and AP Statistics — FRQs, MCQs and the intuition behind them.
KS3 & GCSE Foundation
Plain-English explanations, friendly visuals, small wins that build confidence.
初中数学
人教版与北师大版双线索整理，章节笔记与典型例题逐步上线。
University Foundations
Calculus, Linear Algebra, Probability — bridging A-Level into your first uni term.
IB Math
AA and AI notes, worked examples and intuitive explanations for SL and HL students.
Fresh from the desk.
Recently published notes, trimmed and sorted into their course tracks.
infinite sequences and series
Power series represent functions as infinite polynomials, with convergence determining where the representation is valid.
Rational Number
This chapter introduces positive and negative numbers through real-life examples such as temperature and budgeting, and develops students’ understanding of rational numbers, number lines, opposite numbers, absolute value, and methods for comparing rational numbers.
The Chain Rule, but Actually Intuitive
Why 'differentiate the outside, multiply by the inside's derivative' actually works.
Simple, open, free.
Bilingual by design
Notes can live in English and 中文, with one-tap switching where both versions exist.
Video + notes
Walkthroughs paired with concise written notes.
Auto-tagged
Course and topic tags keep the catalog tidy.
Open comments
Questions and corrections stay open.