Modern school mathematics structure and use / 
Ernest R. Duncan... [et al.]. 
 - Boston:   Houghton Mifflin,   1972.  
 - 316 p. :  ill. ;  29 cm. 
<br/><br/><label>ISBN: </label>0395123496 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Mathematics--Study and teaching (Elementary)
<br/><br/><label>Dewey Class. No.: </label>372.7