Math, rebuilt from the ground up
Start where your math
actually breaks.
Most math struggles trace back to one small thing, further down, that never quite clicked. Answer a handful of questions and Lemma pinpoints that spot — then rebuilds from there, one clear step at a time, until the topics that felt impossible finally make sense.
Free to start · no credit card · about ten minutes to your map.
Why fundamentals first
Every topic rests on the one below it. Skip a crack near the bottom and everything above wobbles.
Precalculus
Functions, trig, and the ideas calculus is built on.
Algebra
Equations, expressions, and solving for the unknown.
Prealgebra
The foundationFractions, negatives, exponents — the ground everything stands on.
You could start anywhere on this ladder. Lemma finds your lowest shaky rung and rebuilds upward from there.
How it works
01
Answer a few questions
A short check-in that ranges across the whole ladder. No studying, no pressure — even how quickly you answer helps us tell what you truly know from what you’re only half-sure of.
02
See exactly where you stand
You get a plain map of your math: what’s rock-solid, what’s shaky, and the one lowest crack that’s quietly holding the rest back.
03
Practice what actually matters
We hand you the single best thing to work on next, check you’ve really got it before moving on, and bring it back just before you’d forget — so it stays for good.
For learners
Never wonder what to study.
No endless videos, no starting from zero on things you already know. Lemma always knows the single best next thing for you — and makes you show you’ve got it before it moves on. Progress you can feel, because nothing is handed to you for free.
Start freeFor teachers
See the real gap, not just the grade.
A wrong answer on quadratics is often a fractions problem in disguise. Lemma traces each struggle down to the fundamental underneath it, so you see exactly what each student is missing — and what to do about it. Point them at a goal and the practice plans itself.
Set up a classWhy it works
It finds the hidden gap
It doesn’t just mark you wrong — it works out which earlier idea the mistake really came from, and sends you there.
You can’t fake it
Answers are checked for real, every time. A concept only counts as learned once you’ve genuinely shown it.
It stays learned
Each idea comes back for a quick check right before you’d forget it, so what you learn today is still there next month.
Find the crack. Fix it. Move on.
Ten minutes from now you’ll know exactly where your math stands — and precisely what to do next.
Find your starting point