Patilla, Peter. <br/><br/>
Starting off with adding and subtracting / 
by Peter Patilla. 
 - Oxford :  Oxford University Press,  2000. 
 - 32 p. :  ill., col ;  25x25 cm. 
<br/><br/><label>ISBN: </label>0199106681 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Addition.<br/>Arithmetic.<br/>Subtraction.