This paper presents a case study describing an approach regarding grade 3 learners that were observed to experience learning difficulties in mathematics. A Namibian grade 3 mathematics teacher shifted from a class- to subject-teaching model as a teaching intervention in the era of Covid-19. The teacher’s knowledge and beliefs about learners with learning difficulties were investigated using semi-structured interviews and lesson observation. The grade 3 learners missed basic mathematical competencies in grade 2 due to the implementation of a rationalised syllabus, and the teacher believes that a substantial mathematical knowledge gap may have a lifelong impact on learners’ understanding of mathematics. Despite the approach, the teacher shows negative beliefs about learners with learning difficulties that may influence the teaching practice