The purpose of this study was to investigate the effects of supplemental on-task and performance contingencies on the acquisition of math skills for elementary school children identified as seriously emotionally disturbed/behaviorally disordered, attention deficit disordered, and students without disabilities. Three experimental conditions were utilized, involving teacher-directed instruction with (a) no contingencies, (b) contingencies for academic performance, and (c) contingencies for academic performance and on-task behavior. The study was designed to measure the effects of these contingency conditions on the number of math problems solved accurately by the study's participants.