Usnick, Virginia E.

Multidigit addition : a study of an alternate sequence - 53-62 - 14, No. 3, 1992

Febrero 1993 = FOCUS ON LEARNING PROBLEMS IN MATHEMATICS

ADICION COMPUTACION DESARROLLO COGNOSCITIVO ENSE\197ANZA MATEMATICA METODOS DE ENSE\197ANZA NUMEROS ENTEROS