Hilary Koll (B.Ed. Hons) - was Mathematics Co-ordinator and Leading Maths Teacher in a Bracknell primary school before training as a Numeracy Consultant prior to the introduction of the National Numeracy Strategy. She has also worked as a part-time Lecturer in Mathematics Education at the University of Reading, teaching on undergraduate, post-graduate and in-service training courses.

With a particular interest in Gifted & Talented students across the 5 - 16 age-range, she is now a full-time writer and consultant in mathematics education. In conjunction with Steve Mills she has written over 150 titles for a variety of publishers, including Hodder and Stoughton, Letts, Ginn, Heinemann, A&C Black, Folens, Schofield and Sims, Egmont and Whizz Education.

Steve Mills (B.A. Hons, P.G.C.E., M.Ed.) - was a teacher of both primary and secondary age children and an LEA Maths Advisory Support Teacher before joining the University of Reading as a Lecturer in Mathematics Education. Here he worked with both under-graduate and post-graduate students in their preparation for teaching mathematics in schools, together with in-service work for practising teachers. During this time he began to write mathematics books for both teachers and children.

He is now a full-time writer and consultant in mathematics education, and, in conjunction with Hilary Koll, has written over 150 books, CDs and audio tapes for a variety of publishers.