Osborn, Roger. <br/><br/>
Extending mathematics understanding 
[by] Roger Osborn [and others] 
 - Columbus, Ohio,  C. E. Merrill Books  1961 
 - 278 p.  illus.  24 cm. 
<br/><br/> Earlier ed. copyright 1960 under the titles Toward improved understanding of mathematics, part I and Toward improved understanding of mathematics, part II, by M. V. DeVault, published in 1960.  Revised in 1969, published separately in two volumes under the titles Understanding the number system and Extending understandings of mathematics. 
<br/><br/>Bibliography: p. 264-271. 
<br/><br/><label>LCCN: </label>61013900  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Mathematics--Study and teaching (Elementary)
<br/><br/><label>LC Class. No.: </label>QA135.5 .O76 1961