00540nam a22001457a 4500008004100000020001500041050002200056100003200078245009600110250001200206260002900218300007500247650004800322700002400370160708b        xxu||||| |||| 00| 0 eng d  a0205483925  aQA 135.6.V36 2007  aVan de Walle, John A.d2007  aElementary and middle school mathematics:bTeaching developmentally /c John A.Van de Walle  a6th ed.  aBoston:bPearson,c2007.  axxvi,509(28) p. : ill.bIncludes bibliographical references and index.  aMathematics-Study and teaching(Elementary).  aJohn A.Van de Walle