CAMEL · Crossfigure Math Puzzle
Crosswords test your vocabulary.
CAMEL tests your number sense.
A crossfigure puzzle game where every clue is real number theory — primes, Fibonacci numbers, GCDs, digit relationships — not arithmetic busywork.
Get notified at launchReal number theory
Primes, Fibonacci and triangular numbers, perfect powers, digit properties — the same ideas that make number theory fun, as puzzle clues.
Always logic-solvable
No guessing required. Every published puzzle can be fully deduced from its clues alone.
Hints that teach
Stuck? Solve Step shows you the next logical deduction and explains whether it follows from one clue alone or needed the rest of the grid.
Three tiers, your pace
From a gentle introduction to dense, multi-step Hard Collection puzzles — with a free Daily Challenge across the full difficulty range.
Starter packs — free
The Hard Collection
Daily Challenge — free, every day