This study investigates the effectiveness of a Game-Based Learning (GBL) itinerary designed to enhance mental calculation (MC) skills related to divisibility in primary education. Grounded in the theoretical perspective of MC as a strategic and adaptive process, the study addresses the gap between performance-based outcomes and the qualitative emergence of flexible strategies. A mixed-methods design was employed with 104 Year 5 pupils divided into an experimental group (Mentematiko) and a control group receiving traditional instruction. Quantitative results showed comparable improvements in execution speed, while the GBL group achieved a markedly greater increase in calculation accuracy. Qualitative validation, based on individual post-test interviews conducted with all participants, revealed that the game-based environment promoted the emergence of flexible and relational calculation strategies rather than procedural reproduction. Social interaction and argumentative practices embedded in gameplay appeared to make mathematical reasoning more visible and adaptive. The study’s originality lies in integrating quantitative performance measures with a qualitative validation procedure aimed at distinguishing genuine flexible mental calculation strategies from numerically correct but procedurally reproduced responses. Methodologically, the findings highlight the importance of analysing actual strategy use when evaluating instructional interventions in mathematics education.
Tortorelli et al. (Sat,) studied this question.