How math works : a guide to grade school arithmetic for parents and teachers /
How math works : a guide to grade school arithmetic for parents and teachers / G. Arnell Williams. - Lanham, Md. : Rowman & Littlefield, c2013. - 325 p. : ill, maps.
Includes bibliographical references and index.
9781442218741
Arithmetic--Study and teaching (Elementary)
QA135.6 / W544H