Topic Study Group 25 (TSG 25) on the role and the use of technology in the teaching and learning of mathematics at lower secondary level discussed this topic over four sessions. These sessions focused on diverse topics such as immersive learning environments in the second session topics as self-efficacy, use of digital technologies outside the classroom and pedagogical aspects of using digital technologies were discussed. In the third session we discussed cultural aspects of technologies in the classroom, and in the last session we discussed communication and the mediating role of digital technologies. The group had contributions from all continents (apart from Antarctica), with a slight overweight of the contributions from European countries. The contributions consisted of five long papers, 21 short papers and eight posters