Spencer, Peter Lincon <br/><br/>
Building mathematical concepts:   in elementary school / 
Peter Lincoln Spencer, Marguerite Brydegaard 
 - New York :   Henry Holt,   1952 
 - ix, 372 p. :  ill. photos;  21 cm. 
<br/><br/> Includes index 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Matemáticas --Conceptos
<br/><br/><label>LC Class. No.: </label>QA 107 S64 1952