Algebra is probably the most difficult aspect of mathematics to teach successfully and it is widely viewed by pupils as "boring" and "pointless". Nonetheless, it provides the key to the great power and potential interest of mathematics. At a time when much is being done to improve children's understanding of number, algebra teaching is too often characterized by ineffective rote learning approaches with little heed being taken of research findings and the potential of technology. This authoritative book shows a way forward.