How should students learn to use a digital tool effectively for mathematical modelling? A part of the research project Modi+ is presented, which investigates the effect of the type of instruction on the use of a digital tool and on mathematical modelling. Prior to receiving instruction on digital tools, secondary school students (N = 209) were tested on their digital tool competencies. After the instruction, students were tested again and solved modelling problems. During the instruction, students of one group learned to use GeoGebra by working on intramathematical tasks, and students in the other group learned to use it by working on tasks related to geometrical modelling. Preliminary results indicate that there are no significant differences in the acquisition of digital tool competencies based on group membership.