An experiment to adjust a programmed college business mathematics text to the level of comprehension suitable for high school students of low ability was prompted by the writer’s awareness of the need for a similar text for high school business majors. The writer was especially concerned with those students who lack ability to attend college, but who go into business offices seeking employment-- positions which invariably require a knowledge of the fundamentals of business mathematics. The case study approach was used in conducting the experiment. The research involved a programmed text of 432 frames, entitled Fundamentals of College Business Mathematics, by Dr. Harry Huffman. Two major objectives were established as a basis for this study. The first objective was to adjust Huffman’s programmed business mathematics text to a level of comprehension of students of below average ability, so that their completed work, without a teacher's help, would be approximately 95 percent accurate. The second objective of the study was to determine whether students could retain the material covered in the programmed unit. This objective was achieved by means of intermediate tests given to each student throughout the unit. Four revisions of Huffman’s original programmed text were necessary to accomplish the objectives of the study. Five panels of student-editors, each panel comprised of three students of below average ability, participated in the research. Revisions to the original programmed text were made on the basis of incorrect responses by individual students working through the unit. Written and oral comments by these students were also taken into consideration in making revisions. Analysis of the data revealed the following results of the total experiment. A total of 104 new frames were added to the original program of 432 frames. This represented a 24.1 per cent increase of frames in the total unit which required an additional 208 responses. There was a total decrease in errors from Panel One to Panel Five of 5.20 per cent. The average score on the six intermediate tests increased 9.1 points from the beginning to the end of the experiment. Results of the experiment lead the writer to conclude that: 1. The error rate of successive panels dropped from 8.03 to 2.83 per cent. This represents a total decrease of 5.20 per cent from the beginning to the end of the experiment. Therefore, it was concluded that senior students, in high school, of below average ability can complete the adjusted programmed unit with an average error rate of less than 5 per cent. 2. Test score average for the panels rose from 78.2 to 87.3, an increase of 9.1 points, from the beginning to the end of the experiment. Therefore, it was concluded that students of below average ability can successfully perform on the retention tests used to measure the result of the programmed unit on fundamentals of business mathematics. / Master of Science