For over a decade, the Govan Mbeki Mathematics Development Centre (GMMDC), a self-sustaining Engagement Entity within Nelson Mandela University’s Science Faculty, has advanced STEM and STEAM education in under-resourced public schools, primarily in South Africa’s Eastern Cape Province (ECP), through innovative Techno-Blended Models (TBM) and tailored Teaching & Learning resources. Employing a participatory action research approach, GMMDC integrates technology, pedagogy, and content expertise to enhance the delivery of the CAPS Mathematics and Physical Sciences curriculum. The GMMDC delivers interactive digital resources and professional development programmes for Mathematics educators, fostering dynamic, inclusive learning environments. It’s TAPS after-school learner incubation initiatives empower thousands of learners annually, driving significant academic progress and expanded access to post-matric STEM opportunities. These efforts strengthen connections between classroom learning and real-world challenges, promoting sustainable educational impact in public schools. Since 2018 the Centre is fostering transdisciplinary learning, critical thinking, and creative problem-solving through STEAM project initiatives. By equipping educators and learners to navigate the complexities of the 21st-century educational landscape, GMMDC drives sustainable STEM development and its transformative impact in the ECP and nationally.