Reys, Robert E. <br/><br/>
Helping children learn mathematics / 
Robert E. Reys, Marilyn N. Suydam, Mary Montgomery Lindquist 
 - 4th ed. 
<br/><br/> College of Education  Bachelor of Elementary Education 
<br/><br/><label>ISBN: </label>0-205-16256-8 
<br/><br/><label>Dewey Class. No.: </label>372.7 R33