A comparison of studies on the relative difficulty of the number combinations
By: [by] Robert T. Rock, Jr., and T. G. Foran.
Contributors: Foran, Thomas George, 1900- joint author.
Series: The Catholic University of America. Educational research bulletins,; v. 5, no. 8
Publisher: The Catholic Education Press
Published: 1931
Place of publication: Washington, D.C
Language: eng
Number of pages: 26
Subjects: Arithmetic -- Study and teaching.
Notes: Bibliography: p. 25-26.