Focusing on students with mild disabilities, this study aimed to examine the effect of STAR problem solving strategy on their a) solving change problems involving one-step addition and subtraction, b) maintaining their acquisition of solving change problems involving one-step addition and subtraction after 1, 3, and 5 weeks, c) generalizing their performance in solving problems to the classroom environment. Three students with mild mental disabilities participated in the study. A multiple probe across participants design was used in the study. The number of problems that students solved correctly was determined by scoring the data. The data are shown graphically and analysed visually. Findings emphasized the effectiveness of STAR strategy for students with mild mental disabilities when solving change problems that involve a one-step addition and subtraction, indicating that those who acquired this strategy could demonstrate the same problem solving performance 1, 3, and 5 weeks after the intervention. Also, students were observed to generalize their strategy performance to the classroom environment. The findings of the research were discussed within the framework of the relevant literature and theoretical views, and suggestions were made for teachers in terms of interventions and for researchers considering further studies.