Ritchhart, Ron <br/><br/>
Making numbers make sense :  a sourcebook for developing numeracy / 
Ron Ritchhart. 
 - Menlo Park, C.A :  Addison-Wesley,  c1994. 
 - 164 p. : ill. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Numeracy.<br/>Mathematical ability.