Best therapy suited to teach daily life skill to a mentally challenged child :

Contingency management is based upon a simple behavioral principle that if the behavior is reinforced or rewarded, it is more likely to occur in the future. " Intervention procedures based upon reinforcement have been successfully used to modify the behavior of mentally retarded person across many populations, settings and target behaviors. Reinforcement approaches are particularly salient with severely and profoundly retarded people because of the critical importance of changing dangerous and / or maladaptive behavior pattern".