The method
Start at the real thing. Step down only when you need to.
Every course is a map of core concepts. You begin on the full question, and the drill moves around you: down to the smaller pieces when one gives you trouble, then back up once they hold.
Core first
A session opens on the question you actually need to be able to do. No levels to unlock, nothing gated.
Step down
Miss it, skip it or run slow, and you get the pieces underneath it, chosen from the work you showed.
Climb back
Warm-ups rebuild the question that's coming next. A concept is yours when you're both right and quick.
By hand
Write it out. Every step gets checked.
Work on a pad with a pen, a finger or a mouse, the way you would on paper. The drill reads your writing and follows your steps, not just the last line.
- Hints show the next step of this exact question, in exact form.
- One hard step? Pick it, and drill that step on its own.
- Every answer comes with the full worked solution.
Typing and the keypad are free. Handwriting is read by Claude, from Anthropic, on your own API key, which stays in your browser.
X and Y are independent, with Var(X) = 2 and Var(Y) = 1. Find Var(2X − 3Y).
Courses
Five courses. One way of practicing.
Each one opens as a map, so you can see what builds on what and start wherever you are.
Math Stats 1
Probability, random variables, expectation, the special distributions and large samples.
Calculus 1
Limits, derivatives, graphs, applications and integrals.
Precalculus
Functions through trigonometry, in one run.
College Algebra
Equations, functions, polynomials, logs and systems.
Trigonometry
The unit circle, identities, and triangles.
Privacy
Private on purpose.
You shouldn't have to hand over anything about yourself to practice math.
No accounts
No sign-up, no email, no name. Open the page and start.
No tracking
No analytics, no tracking cookies, no ads, and nothing loaded from other companies.
Your progress, your file
Progress lives in your browser. Save a backup file whenever you like, and keep it yourself.
Anonymous reports
A report goes out only when you press Send, and nothing in it says who you are.
The details are on the privacy page.
Exposure is the principal component of mastery. Here, I've removed your roadblocks.
A note from the owner