This paper presents our experience of integrating technological tools into our mathematics teaching (in both disciplinary and didactic courses) for student-teachers. In the first cycle of our study, a variety of technological tools were used (e.g., dynamic software, hypertexts, video and applets) in teaching two disciplinary mathematics courses. We found that the tool most preferred by the students was dynamic software, while the applets were almost neglected. In the next cycle, we focused on using various applets in both disciplinary and didactic mathematics courses. We found that if the assignments were applet-oriented, i.e., adjusted to the chosen applet, or vice versa--the applet was chosen appropriately to suit the given assignment--then the students were able to make use of applets in an effective way. Furthermore, the students came to see the potential of applets for improving learning.