MathTrail
Olympiad coach · Grade 3A fence is 12 metres long. Posts stand every 3 metres, including at both ends. How many posts are there?
FreeOpen sourceGrades 1–6
Olympiad maths, in the chat you already use.
An endless stream of checked olympiad-style maths tasks for grades 1–6, in any language, with a diagnosis of the child's mistake and a memory of how they are progressing.
Picked for Galt
Galt's skills
- Enumeration
- Gaps and boundaries
- Parity and alternation
Why this taskAuto-picked
- 72% chance — in the zone
- weakest topic
- repeats a recent mistake: off-by-one
- not practised for 5 days
Pour yourself some tea while your child solves.
Your chat
How a lesson goes
One task at a time, in your own chat.
You sit alongside; your child taps. Beside each step is the card as the chat draws it at that moment.
Ask for a task
Type “a new task, please”. MathTrail picks the topic and the difficulty, the chat writes the task, and a program checks every answer before your child sees it.
Your chat
Answer with a button
Five options, A to E. A tap records the answer straight away — before any explanation, so nothing can talk it into being right.
Your chat
Stuck? A hint, not the answer
The hint points to a way in — draw a smaller fence — and the answer stays hidden until your child commits to one.
Your chat
A wrong answer becomes a lesson
Each wrong option hides a known trap. Once your child answers, the card turns into how the answer went, names the trap from your child's side — “counted the gaps instead of the posts” — then walks through the solution.
Your chat
Ask why, in your own words
Once the answer is in, ask in the chat — “why one more post?” — and the model answers about this very task.
Your chat
An illustration of the chat Progress you can read
The rank reached and the rank of every topic, the mistakes that keep coming back, what comes next — and a review for you of what goes well and what to develop.
Your chat
Why not just ask the chat?
A chat model writes a task in a second — and slips just as fast: two options that are both right, a solution that does not add up, yesterday's task with new numbers. And if your child insists, it happily agrees. MathTrail leaves the model what it does well — writing — and checks everything else with a program.
An olympiad task for grade 3
A number divides by 2 and by 3. Which number could it be?
Two correct answers — nobody checked
Just a chat“An olympiad task for grade 3”
- Two options can both be right — or none.
- Agrees with a wrong answer if the child insists.
- Forgets where your child went wrong.
- You have to know what to ask: topics, levels, what comes next.
- Every task is a one-off, with no model of how children learn.
- No map of what your child already knows.
Chat + MathTrail“An olympiad task for grade 3”
- Exactly one correct option: a solver tries every case.
- The answer is recorded with a tap — no arguing it right.
- Remembers skills and mistakes and picks the next task.
- You just say “a new task”: MathTrail picks the topic and the level.
- A skill model built on research: Elo on top of IRT, 11 ranks.
- A rating for every topic, and a map of which topics build on which.
Tasks do not run out.
Each task is written fresh for your child's topic, level and latest mistake — in your chat's language, not pulled from a fixed bank. Every third is built around their interests.
EnglishРусскийEspañol中文+ any
A program checks the model.
A task reaches your child only after it passes every check: one correct option, the answer reproduced by a solver, readable for the grade, not a repeat, and a picture, where there is one, labelled as the question names it, with no answer on it.
one answersolverreadablenot a repeat
A mistake is a diagnosis.
Every wrong option hides a named trap — “Off by one when counting gaps”, “Missed a case while listing”, “Counted the same thing twice”. The explanation starts from how your child reasoned, not from the right answer.
Trap: counted the gaps, not the posts
What sits behind every task
No need to be a teacher.
You do not have to know olympiad topics or pick a level. Say “a new task” — the coach decides what to practise next and how hard it should be.
A new task, pleasetopic + level: picked
A model built on research.
The chance to solve comes from a skill model used in psychometrics — Elo on top of item response theory — and tasks stay where a child succeeds 70–85% of the time.
P = 0.2 + 0.8·σ(θ + δ − β)A map of skills and topics.
MathTrail knows which topics build on which — ordering and enumeration come before knights and liars — and keeps your child's rating in every topic.
OrderingKnights and liarsEnumeration
Connect
A few steps to the first task.
Claude
Works now · the free plan tooIn Claude, open Customize → Connectors.
Press + Add and choose Add custom connector.
Name it MathTrail and paste the address:
https://mcp.mathtrail.app/mcpPress Continue, and Continue again: the sign-in settings Claude detects need no change. Then press Add, then Connect, and sign in with Google. MathTrail asks to keep one file in your Google Drive — your child's profile. Allow it on Google's screen: without that file there is nowhere to keep the progress.
In a chat, press + → Connectors, switch MathTrail on and say: “Let's do a MathTrail task.”
The free plan allows one custom connector.
ChatGPT
Not in the directory yetFree ChatGPT accounts add apps only from ChatGPT's directory. As soon as MathTrail is listed there, find it by name, connect it and sign in with Google. It is not listed yet.
Until then, ChatGPT's developer mode adds an app by its address, on Plus, Pro, Business, Enterprise and Education plans, on the web: turn it on and add an app with the address above, as OpenAI describes. MathTrail is still being tested in ChatGPT.
You need a Claude or ChatGPT account and a Google account; your child needs neither.
Start with one task.
Add MathTrail to Claude — it takes about two minutes.