To better understand the nature of problems in math learning, a case study was conducted of the specific strengths and weaknesses of a child with a severe math-learning disability. The subject, Adam, was nearly 11 years old when interviews began and had been officially classified as learning disabled due to organic brain dysfunction. A semistructured clinical interview method was employed in the study: tasks or problems, often followed by flexible questioning, were posed to the subject. Interviews lasted from 45 to 90 minutes and were conducted over a 14-month period. Initial clinical interviews revealed that the subject had informal skills and concepts upon which to build, but that his formal math skills were quite deficient. Many weaknesses in formal skills could be traced to a poor grasp of part/whole relationships and base ten notions. Remedial efforts making extensive use of games and activities were implemented. Linking understanding with procedural knowledge, these efforts focused on basic place value and base ten concept skills and resulted in some improvement. Gains made in math ability were perhaps facilitated by affective factors. Over the course of the study, Adam appeared more willing to assert himself, was less defensive, and seemed to have more confidence in his abilities. (RH)