ORCHESTRATING WHOLE-CLASS DISCUSSIONS IN ALGEBRA WITH THE AID OF CAS TECHNOLOGY

This paper describes the practice of a 10th grade algebra teacher during whole-class discussions of equivalence of algebraic expressions some of which contain restrictions. The transcripts of the whole-class discussions were structured into a series of content-process cycles, with each shift in mathematical content signaling the start of a new cycle. Each cycle is also characterized by a particular role played by the CAS technology. The ways in which the teacher involved his students in discussing the mathematics of the task illustrates how algebra can be problematized with the aid of technology in whole-class discussions and thereby potentially lead to students' richer understanding of the mathematical content. The paper concludes with a synthesis of the strategies the teacher used to make the class discussions work.