Abstract
The development of specialised content knowledge (SCK) is crucial for effective mathematics teaching, as it enables teachers to present mathematical ideas clearly and meaningfully to students. This study examines how student teachers’ specialised knowledge of subtracting whole numbers develops within a first-year mathematics content course. Despite extensive research on mathematics teacher knowledge, little is known about how student teachers in South Africa develop SCK of basic operations, such as subtraction. The research examines common procedural errors and reasoning patterns that interfere with students’ understanding of the standard written algorithm and mental calculation strategies. It also discusses potential teaching methods to strengthen SCK and enhance the teaching and learning of mathematics, aiming for a better understanding. A qualitative approach was used to analyse the written responses of first-year Bachelor of Education students in the foundation phase to math problems. These students were enrolled in a mathematics module designed for primary school math specialisation. Content analysis of their responses revealed that, although many student teachers demonstrated procedural fluency, they struggled to provide conceptual explanations and justifications for their solutions, which are key components of SCK. The findings indicate that student teachers often “know how” to perform mathematical procedures but struggle to explain “why” those procedures work. The study concludes that mathematics teacher education programmes should focus more on developing SCK, rather than assuming that student teachers already possess a mastery of elementary math. Improving SCK can encourage teaching math for understanding rather than just following procedures. These findings have implications for designing initial teacher training and ongoing professional development programmes aimed at raising the quality of math instruction in primary schools.