Part 1 Debate, history and challenge: curriculum, community and relevance; years of social and professional change; a brief history of IMPACT; an intervention project; a research project; the IMPACT network. Part 2 Children as tutors: what is IMPACT?; the social context of maths; co- operative learning; peer tutoring; home and schooling as situations for learning; the IMPACT process; IMPACT and the National Curriculum. Part 3 Getting started: National Curriculum process; IMPACT and school policy; staffroom decisions - things to consider; which classes?; IMPACT - how often? which day?; what about resources?; informing the Governors. Part 4 IMPACT in the classroom and the home: planning IMPACT; linking the classwork to the home maths; anticipating follow-up activities; the IMPACT activity cycle; assessment and record-keeping; parental input; listening to parents; designing a response form; patterns of parental contact. Part 5 Designing and selecting materials: designing IMPACT activities; criteria for design; maintaining a variety; preparation in class; follow-up work in groups; selecting IMPACT activities; IMPACT resources; organization in the staffroom; varying the diet; preparation in class; follow-up work; links with commercial schemes; IMPACT flexibility. Part 6 Evaluating, reflecting on practice: re-thinking the scope of evaluation; evaluation in complexity; knowing what to evaluate; rationale for monitoring; starting with institutions; monitoring IMPACT in the school; National Assessment and IMPACT.