Mathematics teachers’ problem-solving content knowledge for teaching in disadvantaged contexts: Insights from a design-based intervention

Mathematical problem-solving content knowledge (PSCK)–a core component of mathematical problem-solving knowledge for teaching–is essential for supporting learners’ problem-solving (PS) proficiency. However, little is known about how PSCK develops among teachers working in disadvantaged contexts. This study examines the development of mathematics teachers’ PSCK in disadvantaged South African schools through a design-based professional development intervention. Four grade 9 teachers participated in two six-month cycles of workshops and classroom-based activities designed to strengthen their PS pedagogy. Data were collected through classroom observations and semi-structured interviews and analyzed using reflexive thematic analysis. Findings show that teachers’ understanding of what makes a mathematical problem meaningful is foundational to their professional growth in PSCK. Growth in teachers’ ability to interpret students’ unconventional solutions was closely linked to their capacity to infer reasoning from diverse solution strategies. Teachers also developed greater skill in problem posing when encouraged to reflect on their own processes of creating and reformulating tasks. While growth was evident among all participants, differences in teaching experience influenced the extent of development. The study broadens our understanding of mathematics teachers’ PSCK in disadvantaged contexts and shows that these contexts do not merely constrain PS instruction; they actively shape the forms of PSCK teachers develop.