The focus of this study is how teachers can use laptops in their classes with TI-Nspire CAS technology and software, with or without concomitant use of handheld devices. Of particular interest has been examining possible changes in teachers' classroom practice and attitudes in using this technology for improving students' math¬ematical learning, problem-solving methods and deeper understanding of mathematics. Eight classes of students in theoretical programmes at upper secondary level in Sweden had continuous access to TI-Nspire CAS in mathematics during a whole semester. They used the software, and in some classes handhelds, during a whole course and also implemented the national test for the course on their laptops. The results show how TI-Nspire software on laptops can be used in regular education in courses at upper secondary level. Its various possibilities, of technical, mathematical and conceptual nature, have had the opportunity to appear in this relatively long study. But also the various obstacles and risks of this type of technology were identified, and the teachers' approaches to them were recorded. The teachers, having quite different prior experiences of technology, showed significant progress during the study, both in terms of management of technology in mathematical work, and when it came to integrating it into a high-quality learning environment. They also testified of the positive impact that the use of technology had on their students’ view of mathematics and of what mathematical activities would include.