Developing Number Knowledge : Assessment, Teaching & Intervention with 7-11-Year-olds, Paperback by Wright, Robert J.; Ellemor-collins, David; Tabor, Pamela D., ISBN 0857020617, ISBN-13 9780857020611, Brand New, Free shipping in the US Following the great success of the earlier books, this fourth book in the Mathematics Recovery series equips teachers with detailed pedagogical knowledge and resources for teaching number to 7 to 11-year olds.