The investigation monitored the digital game-playing behaviours of 428 primary-aged students (aged 10-12 years). Chi-square analysis revealed that boys tend to spend more time playing digital games than girls while boys and girls play quite different game genres. Subsequent analysis revealed statistically significant gender differences in terms of the types of mathematics-rich games students prefer to play. Girls preferred to play games that required problem solving, quantitative computations and the interpretation of graphs. Boys preferred games that required visual/spatial engagement. Given the fact that boys outperform girls on spatial tasks and mathematics assessment items that contain graphics, this study has implications for the development of students' mathematics sense making. (Contains 4 tables.)