00416nam a2200157Ia 4500001001000000003000500010008004100015010001100056040000900067100002000076245005200096260004700148300001000195440003600205650001700241Para_4569CHAP220125s1925    xx            000 0 und d  a203050  cCHAP  aCalhoun, John W  aDeveloping number sense  /c by John W. Calhoun  aKingsville, Texas  :b University of Texas  a15 p.  aUniversity of Texas Bull.; 2542  aAritmética