Digital blocks, equipped with various digital technologies, expand children's play experiences and enrich the process of problem-solving. The purpose of the present study was to explore the effects of digital block play, implemented through a collaborative action research approach, on children’s mathematical problem-solving ability and flow. Thirty-four 5-year-old children (16 in the experimental group and 18 in the control group) from a public preschool in South Korea participated in the study. Children in the experimental group engaged in free play using digital blocks, while those in the control group engaged in free play followed their usual routines without digital blocks. The results revealed that the children in the experimental group exhibited statistically significant improvements in mathematical problem-solving skills compared to the control group. Although the level of flow among children in the experimental group increased more compared to the control group, it was not statistically significant. The present study indicates that digital block play, supported by educator’s close scaffolding, facilitates the mathematical thinking process. The implications of these findings for educational practices and the integration of digital blocks in early childhood education are discussed.