Solving method · 5 minute read
How to Solve a Hidden Number Puzzle
Read the number register, test each clue and eliminate candidates until one answer survives.
Read the guide →The Detective’s Notebook
Find the number.
Prove it.
Learn how to read the register, test number clues and solve Gentle through Fiendish puzzles. Start with the method, then try five free puzzles on your tablet.
Play the free samplerClue guide · 6 minute read
Number Puzzle Clues Explained: Digits, Ranges and Remainders
Understand the arithmetic and digit clues used in The Hidden Number Files, with worked examples.
Read the guide →Solving method · 5 minute read
How to Solve Number Elimination Puzzles Without Guessing
Use a clear elimination record and verify every deduction instead of jumping to an attractive number.
Read the guide →Clue guide · 5 minute read
How to Use Digit Sums and Remainders in Number Puzzles
Work through digit-sum and division clues step by step without mixing up the two operations.
Read the guide →Puzzle design · 5 minute read
Why a Number Puzzle Needs One Provable Answer
See how the register and clues together establish a unique answer and why each clue should matter.
Read the guide →Choosing a level · 5 minute read
Gentle, Standard and Fiendish: Which Number Puzzles Should You Try?
Compare register size, number length and clue count across the three Hidden Number Files levels.
Read the guide →Digital play · 5 minute read
How to Play The Hidden Number Files on a Tablet
Play the free browser sampler and understand the downloadable interactive tablet books.
Read the guide →Choosing a format · 4 minute read
Printable or Digital Number Puzzles: Which Format Suits You?
Compare the printable 30-puzzle PDF with the interactive Hidden Number Files tablet editions.
Read the guide →Choosing an edition · 4 minute read
The Hidden Number Files Editions: What Is in Each One?
Compare the free sampler, 30-puzzle PDF, 100-puzzle tablet book and three-book bundle.
Read the guide →Start free · 4 minute read
Five Free Hidden Number Puzzles: How the Sampler Works
Try five number-elimination puzzles online, from Gentle to Fiendish, and see how email entry and saved progress work.
Read the guide →