Book excerpt: Discover how maths applies to everything with Johnny Ball Join Johnny Ball as he shows your child that maths isn't just numbers and sums, it's a fundamental, incredible, magical way to find out how everything works. From Pi, the amazing number that's vital for so much of everyday life, to perfect proportions - did you know Leonardo da Vinci worked out a person's ear is one-third the length of their face? - discover how numbers, from ancient times to the modern day, have enabled us to explore, build and discover just about everything. With puzzles to solve, conundrums to crack and incredible tricks to show to friends, Johnny Ball will teach your child to become a mathmagician!