The data presented illustrate the diversity of ways of thinking and modes of action: four groups of solvers, who certainly have very different learning experiences, attend different schools and live in different places, realize and recognize the potential relevance of a single tool, GeoGebra, in solving this problem. These four solutions exemplify the kind of symbiosis described by Borba and Villarreal (2005) since the
problem solving strategies and representations they use are revealing of subjects in action with a technological tool; so they can be identified as “students-with-media” or perhaps more accurately as “students-with-GeoGebra”. Still, it is possible to identify common aspects of their problem solving activity: they all represent the rectangular lawn and the triangular flowerbed, they all use “dragging”
to check or verify, and they all analyse and conclude. But what each one takes out of that activity is not entirely the same and seems to be closely related to their ability to use, simultaneously, their mathematical competence and their technological fluency. All participants demonstrated the ability to recognize the affordances of the tool, while
their mathematical and technological activity ranged from an elementary and less
powerful to an advanced and more sophisticated activity. The data suggest that the
differences found are strongly related to the dynamic nature of the mathematical
representations afforded by the tool, in depicting the problem conditions. For example,
the introduction of additional free elements to the figure led to powerful
understandings of the problem, and to generalization. In one production, the invariance
of the area is not only numerically recognised but also geometrically explained; in
another situation the free elements allow seeing the answer as a particular case of a
more general statement; yet another case makes the problem even wider by extending
the several conditions stated and allowing the exploration of a more general problem.
The “invisibility” of mathematical ideas is noticeable in the second production. The
competitors naively accepted the result given by GeoGebra, and used it for attempting
a mathematical justification, without a critical evaluation of such outcome. They lack
critical sense in their analysis of the digital representations, which influenced their
ability to transform information into knowledge (Noss, 2001).
The link between the solving strategy and the type of GeoGebra usage is clear. In
particular, the understanding of the degree of generalisation of the problem and the
consciousness of the affordances of the tool to achieve such generalisation are strongly
interconnected. These are solid evidences of how the spontaneous use of technology changes and reshapes mathematical problem solving. The spectrum of the problem solutions also highlight the effectiveness of the use of digital tools to structure, support and extend mathematical thinking, meaning and knowledge in students’ problem solving. Further research will focus on studying the mediational role of digital
technologies in youngsters’ problem solving activity, in light of what can be called
techno-mathematical fluency (Hoyles, Noss, Kent, & Bakker, 2010).