Green, George F. Elementary school mathematics : : activities and materials / [electronic resource] / George F. Green, Jr.. — Lexington, Mass. : : Heath,, [1974]. — xiii, 512 p. : : ill. ; 24 cm. Includes bibliographies and index. ISBN: 0669845825 9780669845822 LCCN: 73019074 Subjects--Topical Terms: Mathematics--Study and teaching (Elementary) LC Class. No.: QA135.5 / .G675 Dewey Class. No.: 372.7