About Cryptarithm
Cryptarithm is a quiet place to practise arithmetic and logical deduction, one puzzle at a time.
One board, four operations
The game combines addition, subtraction, multiplication, and long division with missing-digit and letter puzzles. Three difficulty levels let players choose where to begin.
There is no daily limit or account requirement. Fresh puzzles are generated on the server, and completed boards stay available until you move on.
Questions worth sharing
Each generated question has a numeric ID that encodes its recipe. Sharing the link preserves the question without exposing your entries, notes, or time.
Teachers can download a clean question image, and players can share a separate image with a QR code. The interface supports multiple languages; word puzzles still use reviewed English vocabulary.