The ubiquity of mobile devices together with the potential to bridge classroom learning to real-world has added a new angle to contextualising mathematics learning. The goal of this research was to evaluate student engagement in a series of mobile learning activities. The study uses critical incident analysis to evaluate the breakdowns and breakthroughs of mobile learning. Twenty-four Primary 7 students participated in the study. The mobile learning activities were found to have facilitated visualisation, encouraged reflection and promoted active learning. However, some issues regarding mobile use affected student engagement with the activity. The challenges identified highlighted the role teachers play in designing and carrying out novel technology use.