Difficulty guide
Gentle, Standard and Fiendish: Which Number Puzzles Should You Try?
The same elimination method works at every level. What changes is how many candidates you must test, how long the numbers are and how many clues you need to combine.
Gentle: learn the routine
Gentle puzzles use 30 two-digit candidates and four clues. They give you space to practise crossing out numbers, adding digits and verifying the final survivor without managing a huge register. The free online sampler starts with one Gentle puzzle, then two Standard and two Fiendish.
- 30 candidates.
- Two-digit numbers.
- Four clues.
Standard: keep your records tidy
Standard puzzles use 48 three-digit candidates and five clues. The first and last digits can now be far apart, and a digit sum involves three figures. Work through the register in a consistent order; mark each clue as used so you do not accidentally skip a row.
- 48 candidates.
- Three-digit numbers.
- Five clues.
Fiendish: be precise, not fast
Fiendish puzzles use 72 four-digit candidates and six clues. More numbers means more opportunities for a missed digit or arithmetic slip. Use broad filters first, then check the smaller survivor set carefully. There is still one verified answer; difficulty comes from sustained attention and intersecting rules.
- 72 candidates.
- Four-digit numbers.
- Six clues.
Choose an edition
The 30-puzzle print edition has ten puzzles at each level. The single 100-puzzle tablet book has 30 Gentle, 40 Standard and 30 Fiendish puzzles. The three-book tablet bundle contains 100 different puzzles in each level. All three paid editions are available now.