Mental mathematics promotes flexible calculation strategies, but the shift from basic methods to formal algorithms reveals gaps in teachers’ PCK, particularly in supporting diverse strategies (Venkat, 2024). Addressing these gaps is crucial for improving learners’ mathematical reasoning and skills. This study explores teachers’ understanding of mental mathematics and how it supports learners’ abilities. Specifically, it investigates what teachers know about mental mathematics, how they can teach it effectively, and the challenges they face.
The qualitative research involved six female teachers who primarily teach early years mathematics. Data were collected through questionnaires and interviews within a Professional Learning Community. The study used the Refined Consensus Model (Carlson et al., 2019) to analyze the data, which views PCK as a dynamic process shaped by teaching and reflection. The model identifies three types of PCK: personal (individual knowledge), collective (field-wide knowledge), and enacted (classroom application).
Findings revealed that teachers’ personal PCK was limited and unclear. Although they described mental mathematics as basic counting and “in the head” calculations, their enacted PCK suggested students used external tools like fingers and counters. Teachers noted challenges such as language barriers, lack of professional development, and students’ struggles with basic concepts. The study emphasises the need for more focused training and support for teaching mental mathematics effectively.