We present a longitudinal VR-study conducted with second-graders, focusing on the practical challenges and insights gained from integrating immersive room-scale VR math learning in a primary school setting. Over six weeks, twenty children participated in a total of 197 training sessions, resulting in 3540 min of VR gameplay. Our primary goal is to provide methodological insights into the feasibility and impact of VR as an educational tool for young children. Our findings indicate that the VR sessions were generally highly engaging, safe and suitable. Instances of cybersickness were rare; however, issues with headset fit and isolated collisions occurred, underscoring the need for sufficiently large play areas with proper buffer zones and dedicated supervision. Children quickly developed VR competence and demonstrated increased confidence in interacting with the virtual environment and engaging with learning content over time. Our findings contribute to understanding the potential of VR for young children in educational contexts, offering key insights into feasibility and safety of VR learning applications and methodological considerations for future studies.