Mike Ollerton taught for 25 years in schools and 10 years in teacher training. He is now a freelance consultant. Anne Watson is Reader in Mathematics Education at the University of Oxford. Her interests include exemplification and task design in mathematics teaching and learning; the use of fine-grained approaches to analysis of mathematics interaction within socio-cultural perspectives; the role of mathematics education in social justice issues. She teaches PGCE Secondary Mathematics and leads a small group of Mathematics Education researchers who focus on mathematical thinking in school contexts.