Abstract
This interpretative phenomenological study adopted the Community of Inquiry framework to explore 30 South African teachers’ experiences of the effectiveness of Grade 9 online mathematics teaching resources. A survey questionnaire with open-ended questions and a semi-structured interview guide were used to obtain data on the teachers' experiences. Data were analysed using an inductive thematic coding approach. The findings were that the teachers positively experienced the efficacy of online teaching materials for their professional development in terms of cognitive, social, teaching and learning presences. Using WhatsApp groups to share and discuss the online materials enhanced a common identity (social presence), deep engagement with the mathematical and pedagogical content knowledge of the materials (cognitive presence), (peer) teaching and (peer) learning from one another via WhatsApp (social media) chat groups (teaching and cognitive presences) that collectively eased curriculum implementation and enhanced student learning. However, limited facilitator teaching presence and limited internet access for both teachers and learners constrained the platform's benefits. Participating teachers reported spending at least three hours per week searching for online teaching resources, sometimes fruitlessly, indicating a need for more digital literacy training. The study makes a valuable contribution to our understanding of the potential benefits of online resources for teaching complex mathematics topics such as fractions and familiarity with the obstacles that need to be overcome. The more teachers and students turn to online resources, the more the findings of this study can inform the development of such resources to improve mathematics learning outcomes for schools in contexts of disadvantage.