Robyn PierceComputer Algebra Systems (CAS) are used in middle secondary classrooms as a tool to support learning and sometimes in preparation for senior secondary mathematics. This paper presents an analysis of strengths, weaknesses, opportunities, and threats identified in the literature and perceived by twelve secondary teachers working with year 9 and 10 students. CAS is valued for calculation and manipulation capabilities, the option of alternative representations, the opportunity for systematic exploration, and for prompting rich discussion. However the technical overhead, initial workload for the teacher, and unresolved questions about the contribution of machine and by-hand work to learning must also be considered.