Pitched at the perfect difficulty level ... clearly and intelligently written ... Anyone with a slight geeky bent to them, whether they be adult or teenager, will find plenty to edify, tickle and tantalise them. It'd make a wonderful present ... I can't wait for the next volume. Highly recommended.
Bookbag
There are jokes, puns, hints on code-breaking and a dollop of the unexpected. You won't have learned any of this in school but if you have a mathematical bent and a logical mind you will soon be teasing out the answers.
Good Book Guide
An ideal present for anyone addicted to Sudoku-like puzzles and beginning to wonder what might lie beyond
Spectator
This is not pure maths. It is maths contaminated with whit, wisdom, and wonder. Ian really is unsurpassed as raconteur of the world of numbers. He guides us on a mind-boggling journey from the ultra trivial to the profound.
Jeremy Webb
New Scientist
A perfect gift for a clever child
Daily Telegraph
As the professor darts randomly from 'digital cubes' to 'the hairy ball theorem' with boundless playful curiosity, even those with only a sluggish interest in maths will find something to amuse and amaze
Sunday Telegraph