This paper presents the result of a research aiming to analyze how a study group, of prospective mathematics teachers, used dynamic geometry software in planning activities for a teaching practice. Before practicing with students, the group read and discussed papers from journals, explored Geogebra, dynamic geometry software, and planned a workshop to be held with students at high school level. A special highlight is given to the unpredictability which occurs in a ICT-based environment, and how this establishes a risk zone. Thus there are both technical and mathematical content related risks. The results show that a collective theoretical study was essential for the prospective teachers not to be paralyzed when facing unpredictability. Episodes are discussed illustrating how a risk zone can turn into a fruitful learning environment. The group provides conditions for reflecting and facing the unpredictability of a computer-based environment, stimulating professional development.
High school; Mathematics teaching; Dynamic geometry; Information technology and communication; ICT
