CEMASTEA's professional training programs stand out due to their unique and effective approach of using teachers to train other teachers through a cascade model. This training concept was implemented to secure teacher buy-in and a broader national outreach. County trainers, the lead teachers chosen through a competitive process, play a crucial role in training teachers on behalf of CEMASTEA at the County level.

County Trainers (CTs) are exemplary mathematics and science teachers and critical players in planning and implementing SMASE programmes in the Counties.  Their number depends on the population of STEM teachers in each County but there are about 1,200 County Trainers spread across all 47 counties in Kenya.  Trained at the national level, they implement downstream training at the Counties where they cascade training on Pedagogical Content Knowledge (PCK) and skills to the classroom teachers within their respective counties. Each of the four STEM subjects, Biology, Chemistry, Physics, and Mathematics, is represented. They also assist in the promotion of continuous professional development among STEM teachers by providing mentorship and support. Among these great teachers is a dedicated team called County Trainers Representatives (CTRs), who coordinate other County Trainers for the smooth and seamless implementation of CEMASTEA activities in the counties.   

Several County Trainers have walked the SMASE Project and CEMASTEA journey since its inception.  The majority of those who started this journey as classroom teachers have advanced and now occupy senior positions in the education and public service sectors.. Some County Trainers have advanced in their careers to be school leaders, including Nancy Mwaura, Principal, Queen of Peace Nembu Girls Secondary, Gatundu Kiambu; Scolastica Mbaa Principal, Moyeni Girls Kinango, Kwale; Jane Musungu, Principal, Precious School Kapsambo; Daniel Mwachi, Principal, Vihiga Friends High School among others.  Overall, County Trainers are pivotal in ensuring the success, sustainability, quality and effectiveness of CEMASTEA’s STEM education programmes and contributing to the overall improvement of STEM education in the country.