The purpose of this project was to determine if the method of subtraction of integers taught to seventh grade students affected their mathematics achievement or retention. Computation, concept, and problem-solving sections of the California Achievement Test were given as pretests and posttests. An investigator-constructed test of the addition and subtraction of integers was also used as a pretest, posttest, and as a retention test one month after completion of the treatments. The project was divided into two studies. The first study involved 140 students and three teachers, and compared the Complement Method of subtraction to the Related Facts Method. Results showed a statistical difference in the area of concepts, favoring the group taught the Related Facts Method. No statistical differences were found in the areas of computation, problem-solving, or addition and subtraction of integers. The second study involved 90 students and two teachers, and compared the Complement Method of subtraction to the Systems Method. Statistical difference on the retention of the subtraction of integers favored the Systems Method. Statistical difference on the retention of the addition of integers favored the Complement Method. No statistical differences were found in any areas of immediate achievement in the second study. (Author/DT)