This study explored the performance of 75 seventh-grade students with and without disabilities, educated in inclusive mathematics classes, on open-ended, problem-solving mathematics assessments. In the study, approximately half of the students used a graphing calculator on the first assessment and not on the second assessment (n = 35; 46.7%), whereas the other half used it on the second assessment and not on the first (n = 40; 53.3%). The results indicate that all students did better when using a graphing calculator, regardless of the order of calculator use (i.e., Assessment 1 or 2). The results also suggest that calculators may not be a valid accommodation for some students with disabilities on assessments. This study has implications for providing calculators as accommodations on mathematics assessments. (Contains 1 table and 2 figures.)