We assessed the academic performance and behavior of 121 nondisabled elementary boys and 107 boys with attention-deficit hyperactivity disorder (ADHD), ages 7.4 through 14.5 years. Students completed computer-generated tasks of reading, computation, and math problem solving, and we recorded two performance measures (accuracy and speed) and three behavioral measures (vocalizations, head movements, and bottom movements). Our purpose was to determine the effects of ADHD on conceptual and computational math. For greater precision than has been available in past math research, we held reading and problem structure constant, while recording speed of processing, number recognition, and motor response. Our analysis yielded significantly lower problem-solving scores in specific math concepts and slower computational performance for the boys with ADHD. These findings demonstrated the educational implications of attention deficit disorders for mathematical skill and the need for interventions that are geared more specifically to these deficits, and that also provide accommodations for reading complexity and length, visual-motor skill, feedback, and self-pacing.