THIRD-R STRUCTURES: THE MATH RESEARCH PROGRAM IN PRIMARY GRADES Weininger, Otto Toronto, OISE Press, 1991. 47pp, paper, $11.80 ISBN 0-7744-0377-2. CIP Subject Heading: Mathematics-Study and teaching (Primary). Professional Reviewed by Gail K. Lennon Volume 20 Number 3 May 1992 Within the pages of this practical and theoretically based volume is a wealth of information for the Primary teacher, administrator and parent. The language is user friendly for those at all stages of child development theory. The book is dearly and logically organized. The author deals with the role of the teacher in the play-based Primary mathematics program, and the last chapter contains information on the evaluation of the play-based program. It would be a very useful tool for explaining the merits of play-based learning to parents and board members. There is an excellent list of questions to use in discussing progress with children. This is followed by an outstanding glossary of mathematical terms and a list of teacher comments that would encourage students to use mathematical language in their play. The appendix contains a list of necessary materials and a bibliography of current references on the topic for further reading. It is very difficult to find a book on the topic of play that contains a solid philosophical base and proof of successful application of this philosophy in real-life classrooms. Third Structures accomplishes this task admirably. This book is a "must have" for Primary teachers, beginning administrators of Primary classrooms, and parents. The veteran teacher will find it a practical guide in evaluating his or her Primary mathematics program. In my early days of struggling with the value of play in my kindergarten and grade 1 classrooms, I would have welcomed such a useful handbook! Gail K. Lennon Walkerton District Secondary School, Walkerton, Ont.