A MTS procedure to teach subtractions involving equivalence class formation nets was evaluated to teach people with mental retardation.The firststepwas thetestsoftherelationsinvolved inthesubtraction operation - numerals from 1 to 9 (class ABC) and operators that composed the operation (class FGH). The second comprised tests/training of the relations between the sentences - spoken (I), with sets(J) and with algorisms (K) - to values from 1 to 5. The third step consisted on the training/tests of the relation between sentence (class IJK) and result (class ABC), to values from 1 to 9. The results showed that the procedure allowed the emergency of some relations in test sessions, suggesting its potentiality to the acquisition of adequate responding to new numerical stimuli combination. It is considered that the procedure must be tested in other populations using, besides mathematic, other arithmetic operations.
stimulus equivalence; subtraction; mental retardation; experimental analysis of behavior
