TY - BOOK AU - Hartung, Maurice L. AU - Knowles, Lois AU - Van Engen, Henry TI - Teaching guide : seeing through aritmetic U1 - BMG-BANT COL R513 HARt PY - 1961/// CY - Chicago: PB - Scott, Foresman, KW - ARITMETICA-ENSEƑANZA ELEMENTAL KW - ARITMETICA-GUIAS KW - ARITMETICA-PROBLEMAS KW - EJERCICIOS KW - ETC N1 - Maurice L. Harting, Henry VAn engen and Lois Knowles; <1961> ER -