This book is part of a book series called Big Questions .

This book has been graded for interest at 7-10 years.

There are 96 pages in this book. This book was published 2009 by DK Publishing (Dorling Kindersley) .

Johnny Ball has masterminded and presented more than 20 children's television series about maths and science. He is best known for the hit BBC series Think of a Number . No-one is better known for making maths not just easy to understand but genuinely fun and fascinating.