Arithmetic → graduate level

Learn all of mathematics. And actually keep it.

Most apps teach you something and move on. Erudia keeps track of every concept you've studied and schedules a review right before you'd forget it. A few minutes a day, and the math stays with you.

No credit card. Begins with a quick check to find where you already are.

41chapters
698skills mapped
FSRSretention engine
Freeto start
π
You don't forget because you're bad at math. You forget because nothing brought it back.

Cramming feels productive and disappears in a week. Erudia schedules every concept on a forgetting curve, so five minutes of review today saves you from relearning a whole chapter next month.

How it works

Every session does three things.

1

Learn visually

Short lessons built around interactive widgets you can drag and adjust, not videos to sit through. You see what a concept does before you're asked to use it.

2

Practice with real feedback

Miss a question and it tells you what went wrong: a sign error, an off-by-one, a missing step. Then it brings that skill back until it holds.

3

Reviews, perfectly timed

The engine estimates when each skill is about to fade and brings it back right then. Your time goes to what's slipping, not what you already know.

One connected map

From counting to category theory, and everything in between.

Every skill is linked to the ones it depends on, so you can start anywhere and always know what comes next.

ArithmeticAlgebraGeometry TrigonometryPrecalculusCalculus Multivariable CalculusLinear AlgebraDifferential Equations ProbabilityStatisticsDiscrete Math Number TheoryGraph TheoryGame Theory Real AnalysisComplex AnalysisTopology Abstract AlgebraMeasure TheoryStochastic Calculus Category TheoryCryptography+ competition math
Why it's different

Built like a tutor, not a playlist.

It models your memory

An FSRS spaced-repetition engine tracks the strength of every skill and times reviews to your personal forgetting curve — so a review lands the day before you'd have lost it, not weeks too late.

A real knowledge graph

Hundreds of skills wired by prerequisite. Nothing unlocks before its foundation, and gaps get caught before they compound.

Adaptive placement

A short diagnostic finds what you already know, so you skip what you've covered and start where it's useful.

Interactive, not passive

Drag a vector, sweep an angle, watch a Riemann sum converge. You build intuition by doing, not watching.

Target any goal

Pick a topic and get the shortest ordered path to it — prerequisites first, skipping what you've already mastered.

Honest progress

A skill counts as mastered only when it survives real spaced reviews — not the moment you first get it right. Your map stays honest about what's solid, what's fading, and what's next.

Pricing

Free to start. Upgrade when you want the rest.

Free
$0
  • Adaptive placement
  • The full foundations track
  • Spaced reviews + progress map
  • Interactive lessons
Get started
Premium
$7.99 / month
  • Every chapter, through graduate level
  • Olympiad & competition tiers
  • Mastery modes + deeper analytics
  • A public ★ PRO badge on the leaderboard
Go Premium

Pricing shown is indicative for the upcoming launch.

Start where you are. Go as far as you want.

Five minutes to find your level, then a clear path from there to wherever you're headed.