Numerous research studies on digital educational games (DEGs) focused on whether they help improve children’s learning performance. Nonetheless, only a few studies sought to address how children learn through DEGs. We were motivated to bridge this gap through an empirical study with the eye-tracking methodology. A total of 94 five-year-olds were involved in the study. They were asked to play with a DEG or cardboard game on numeracy. We analysed how fixation duration (a proxy for attention) was related to learning strategies based on the children’s achievement level. The main findings include: the DEG did not yield any significant learning effect but its cardboard version did; the children’s performance for recall-based tasks were significantly worse than that for recognition-based task; the achievement level played a significant role in varying attention given to the objects of the games. Reflections on applying the eye-tracking methods to young children were also discussed.