The initial training of mathematics teachers in Spain can start in the
final year of the mathematics degree when the students, and future
teachers, select courses related to teaching the discipline. At that
time, since over the next two years they will probably be certified
to enter the profession, it is worth asking oneself what mathematical knowledge they should have and what is needed to teach at the
secondary education level. This paper describes one case study in
which a group of final-year students solves a task containing aspects
of mathematical understanding that are present in solving problems
using GeoGebra. This was done using a solution protocol intended
to emphasize the different possibilities offered by GeoGebra, presenting three approaches for the solution: dynamic, numeric and
algebraic. We noticed that the use of technology is key to bringing out some of aspect and to demonstrating an understanding of
mathematics for teaching.
