‘24’ The Challenging New Number Puzzle (Paperback - 2010)

'24' is a challenging new cross-number puzzle that combines problem-solving, logical thinking and elementary Mathematics. The puzzles involve the level of Maths taught at school, featuring brackets, powers, roots, decimals, factorials, negative numbers, estimating and so on. Solvers are advised to tackle them with the aid of a simple scientific calculator, although they may enjoy the challenge of attempting them without one.

The puzzles take the form of a symmetrical grid and twenty-four clues. A selection of four digits is given at the top of each puzzle which the solver must combine in the correct way in order to obtain the number 24 each time.

Each puzzle should take between 30 and 50 minutes to solve.

John Enock has been teaching Mathematics for over twenty-five years in the UK, having always a special interest in recreational Mathematics including games and puzzles of all kinds.

He started to write cross-number puzzles about ten years ago and has had puzzles published in The Times newspaper, two specialist crossword publications called Tough Puzzles and The Magpie, and The Penguin Collector's Society Magazine.

His first book of number puzzles Cryptic Crossnumbers was published in 2008 by Tarquin Books, UK.