Edition guide
The Hidden Number Files Editions: What Is in Each One?
Start with five free browser puzzles. If you enjoy the method, choose between a short printable set, a larger mixed-level tablet book or separate books for each level.
Free online sampler
Five puzzles (one Gentle, two Standard and two Fiendish) play in your browser after you enter an email address. Marketing updates require a separate optional choice. No payment is required. The sampler saves progress on the device and browser where you play.
30-puzzle printable PDF · £3.99
Ten puzzles each at Gentle, Standard and Fiendish, plus solutions, in a PDF designed for printing. This is the smallest paid edition for someone who prefers solving on paper. It is not the interactive tablet file.
100-puzzle digital book · £6.99
A downloadable interactive HTML book with 30 Gentle, 40 Standard and 30 Fiendish puzzles. Tap to cross out candidates and mark clues on a tablet or computer. Progress stays in the browser you use.
Three-book digital bundle · £12.99
Three separate downloadable interactive books: Gentle, Standard and Fiendish, each containing 100 different puzzles. This is 300 puzzles in total, not three copies of the mixed book. Choose it if you want a full progression through the levels.