Erudia teaches all of mathematics on a spaced-repetition engine that times every review to the moment just before you'd forget. Learn math free, start where you actually are, and watch it stick.
No credit card. Begins with a quick check to find where you already are.
Most apps teach you something and move on. To learn math and keep it, you need the right concept brought back at the right time. Erudia does exactly that.
An FSRS retention engine models the strength of every skill and schedules each review on your personal forgetting curve. A short diagnostic places you, hundreds of skills are wired by prerequisite so nothing unlocks before its foundation, and a concept counts as mastered only once it survives real spaced reviews.
Learn visually with interactive widgets you drag and adjust instead of videos to sit through. Practice with feedback that names the sign error or off-by-one, not just a red X. Then reviews land exactly when a skill is about to fade, so your time goes to what's slipping rather than what you already know.
41 subjects, from arithmetic to graduate level, each linked to the topics it depends on. Start anywhere and always know what comes next.
More ways to practice: sharpen speed in ranked 1v1 math duels and track your standing on the math leaderboard.
Adaptive placement, the full foundations track, interactive lessons, and spaced reviews are free, no credit card required. Premium opens every chapter through graduate level plus olympiad and competition tiers when you're ready to go further.
Yes. You can learn math free: adaptive placement, the full foundations track, interactive lessons, and spaced reviews cost nothing and need no credit card. Premium ($7.99/month) unlocks every chapter through graduate level plus olympiad and competition tiers.
Yes. Erudia starts at counting and arithmetic and builds up through algebra, geometry, and beyond. A short placement check finds where you already are, so you can learn math from the ground up or jump straight to where the gaps begin.
That depends on where you start and how far you want to go, but the method is built for a few minutes a day rather than cramming. Spaced reviews keep what you learn from slipping, so steady short sessions move you forward faster than long ones you forget by next week.
All of it. 41 subjects span arithmetic, algebra, geometry, trigonometry, precalculus, calculus, multivariable calculus, linear algebra, differential equations, probability, statistics, number theory, discrete math, real and complex analysis, abstract algebra, topology, and graduate-level topics, plus competition math.
That is the whole point. An FSRS retention engine models the strength of every skill and schedules each review for the moment just before you would forget it, so the math you learn stays learned instead of fading after the test.