HILARY KOLL was a Mathematics Co-ordinator and Maths Teacher in Bracknell primary school and has also worked as a part-time lecturer in Mathematics at the University of Reading. Hilary has more recently turned her attention towards publishing and is now a full-time writer and consultant in mathematics education. She has written over 150 titles for a variety of publishers, including Hodder & Stoughton and QED. STEVE MILLS was a teacher of both both primary and secondary age children before lecturing at the University of Reading in Mathematics Education. Here he worked with both under-graduate and post-graduate students in their preparation for teaching mathematics in schools. During this time he began to write mathematics books for both teachers and children. Steve is now a full-time writer and consultant in Mathematics education and has written over 150 books for a variety of publishers. VLADIMIR ALEKSIC was born in Serbia and Montenegro and has a wealth of illustration experience. His style is often described as 'semi-realistic', as his illustrations have a clear comic book influence. He has worked for clients including DK, where he illustrated Pirate Attack! and Clash of the Gladiators.