BIGGS, Edith Ethel. Freedom to learn: An active learning approach to mathematics - Don Mills, Ont., Reading, Mass., : Addison-Wesley (Canada) Ltd , 1969. - 205 p . : ill . ; col . picture ; 24 cm. Includes index. For student teachers and teachers. ISBN: 0201005727 9780201005721 Subjects--Topical Terms: MathematicsActive learning. Dewey Class. No.: 510