Students' mathematical reasoning while engaging in a strategy game

Since 2009, Danish math curriculum guidelines for mathematics have emphasised reasoning competency as a key goal. Yet, teachers and students struggle with implementing and engaging in reasoning tasks, partly due to inadequate teacher support and the fact that teaching materials for primary and lower secondary grades only touch on reasoning implicitly, if at all (Gissel et al., 2019). We present a preliminary analysis of a qualitative design study aimed at improving Danish lower primary school students’ reasoning competencies by engaging them in a specially designed strategy game, The Lighthouse, which is a variant of Brousseau’s Race to Twenty (Brousseau, 2002). Our research question is: How does the use of a strategy game affect how students engage in the phases of exploration, conjecturing, and justifying in the reasoning and proof cycle?