Math steps :  Level 7 /. 

 - Boston :  Houghton Mifflin,  c2000. 
 - 361 p. :  ill., col ;  28 cm. 
<br/><br/> Includes glossary. 
<br/><br/><label>ISBN: </label>0395985390 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Mathematics.