Cruikshank, Douglas E. Teaching mathematics to elementary school children : a foundation for the future / Douglas E. Cruikshank, Linda Jensen Sheffield. - Columbus : Merrill, c1988. - ix, 396 p. : ill. ; 28 cm. ISBN: 0675206197 (pbk.) LCCN: 90074184 Subjects--Topical Terms: Mathematics--Study and teaching (Elementary).