<p>This study examines the implementation of environmental education in the STEAM approach for sustainability. A STEAM model for engaging students in environmental sustainability programs through problem-solving. The main focus of the study was to identify how the pre-service teacher practices the STEAM innovation in mathematics classrooms. Five pre-service teachers who conducted pedagogies internships in different schools were selected purposively as the research participants. Designed Based Research (DBR) was adopted to support the pre-service teachers in developing and exploring their practices within the framework of this STEAM project. This study was designed in 3 stages. The first stage involved identifying and selecting STEAM resources (Analysis and Exploration). The second stage included implementing the school's STEAM project (Design and Construction). The third stage evaluated the practice of the STEAM project (Evaluation and Reflection). The findings were that the STEAM projects implemented by the five pre-service teachers shared similar teaching approaches even though their contexts differed (dance, solar panel, Batik, waste management, and tessellation). These findings provide insight into how different STEAM projects can support the pre-service teachers in integrating environmental education into the STEAM approach for sustainability.</p>