Designing To See And Share Structure In Number Sequences

This paper reports on a design experiment in the domain of number sequences conducted in the course of the WebLabs project. We iteratively designed and tested a set of activities and tools in which 10-14 year old students used the ToonTalk programming environment to construct models of sequences and series, and then shared their models and their observations about them utilising a webbased collaboration system. We report on the evolution of a design pattern (programming method) called ‘Streams’ which enables students to engage in the process of summing and ‘hold the series in their hand’, and consequently make sophisticated arguments regarding the mathematical structures of the sequences without requiring the use of algebra. While the focus of this paper is mainly on the design of activities, and in particular their epistemological foundations, some illustrative examples of one group of students’ work indicate the potential of the activities and tools for expressing and reflecting on deep mathematical ideas.