Background: Teachers teach mathematics by focusing on procedural knowledge (what steps to follow when doing mathematics) and pay scant attention to the conceptual understanding that underlies these procedures such as double-digit addition or subtraction and overall additive and multiplicative relations. They teach concepts in a haphazard way instead of looking at them from a convergent perspective of concepts that a child builds, one after the other.Aim: This study explores what Grade R teachers know about young children’s specific developmental numerical cognition and if they infuse their understanding of number concept development in their pedagogy.Setting: Samples of 15 female Grade R teachers were purposefully selected from five schools in what was previously a racially segregated living area in South Africa.Methods: This research design is a descriptive case study. Data were collected using semi-structured interviews and observation notes documented during workshops and when the teachers implemented their learnings in their classrooms.Results: The main finding was that although teachers could reflect on the model of number concept development they had learned, they found it hard to infuse their knowledge into a strictly structured curriculum.Conclusion: Despite the Meerkat Maths programme offered to the teachers, they could not rely on their intuitive pedagogy, coupled with the model of number concept development that they had learned because of the strict demands of the school curriculum content with which they had to comply.