Math practice · reimagined
Primes
Turn Primes into a fight you actually want to win. Every problem is an attack — solve it faster than your opponent and you land the hit.
Ages 4–99+ · no download · plays in your browser · 23 languages
How it works
Primes
Pick a fighter, choose Primes, and trust your numbers. The faster and cleaner you solve, the harder you hit — from gentle early grades all the way to Olympic-level challenges.
A prime number can only be built one way: 1 times itself. Nothing else divides into it evenly — it refuses to be split into equal groups.
Up here the numbers get bigger, so you test them. Try dividing by 2, then 3, then 5, 7, 11, 13… if any of them fits with nothing left over, the number is NOT prime. Watch out for sneaky ones like 91 — it looks prime, but 7 × 13 = 91, so it's hiding a factor.
Read whether the question wants the prime or the odd-one-out, then tap your pick.
— Quick answers —
Primes: the short FAQ
- Is Primes free to play?
- Yes. Primes is free to play right in your browser — the whole curriculum, no download, no signup. Paid plans later unlock the full fighter roster, every stage and saved progress.
- Who is Primes for?
- Anyone from 4 to 99+. The early grades stay gentle for beginners, while the higher tiers will make even the confident sweat.
- Do I need to download anything to play Primes?
- Nope. Primes runs in any browser, on a laptop, tablet or phone.
- Can Primes be used in the classroom?
- Absolutely. Teachers run Primes with a whole class and track who's improving — see the schools plan for per-student pricing and a teacher dashboard.