Childcraft the how and why library volume 13  Mathemagic 

 - New York  World Book childcraft International, Inc.  1961 
 - 303p.  ill.  25.5 cm. 
<br/><br/> Includes index. 
<br/><br/><label>ISBN: </label>0716601826 
<br/><br/><label>Subjects--Topical Terms: </label>
<br/><br/><label>Dewey Class. No.: </label>371.2