Robert TimlinRobert Timlin studied mathematics and theoretical physics then undertook further studies leading to the award of a PhD. Rob qualified as a teacher after a PGCE where he studied with co-author Paul Chambers. Rob has taught in several schools inthe North West of England and in London. He has been both a successful Head of Department and Assistant Headteacher. He has also worked as an educational consultant, advising local authorities and other public and private bodies on the teaching of mathematics. He has taught on a number of higher education courses, including the establishment of a successful PGCE Mathematics course at Liverpool John Moores University, and the role of Principal Lecturer in Mathematics Education at Manchester Metropolitan University. He has taught on undergraduate teaching courses and on mathematics degree courses as well as on Master's degrees in educational practice.