Making sure of arithmetic :  grade four / 
Robert Lee Morton... [et al.]. 
 - New York :  Silver Burdett,  c1946. 
 - iii, 345 p. :  ill. ;  22 cm. 
<br/><br/> Includes index. 
<br/><br/>336  336 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Mathematics<br/>Arithmetics
<br/><br/><label>Dewey Class. No.: </label>510 / M367m