Students who learn mathematics with CAS calculators are likely to develop new practices for doing and recording mathematics. Students discussed in this paper were able to use CAS calculators in examinations, making their own decisions about what to document as written records for solutions to problems. A comparison of some features of written records produced by these students, with an achievement matched random sample of students with only graphics calculators, gives insight into the new practice which is emerging. Students who had learned with CAS wrote generally shorter answers, used more ordinary words and used function notation more frequently but they did not over-use non-standard calculator syntax. [For complete proceedings, see ED489632.]