The introduction of the school subject Mathematical Literacy (ML) was to develop numerate and well informed citizens in South Africa. However the success of the subject is dependent on the ways in which teachers mediate the subject with their learners. The purpose of the study reported on in this article was to explore the extent to which the approaches used by ML teachers supported the learners' participation in the contextual settings. The article focuses on one case study that was drawn up from three lesson observations and an interview with one ML teacher. The data was synthesised using a narrative analysis approach. The study found that the teacher's explanations of contextual terms were sometimes incorrect and irrelevant. Her discussion often sidestepped the main issues and did not help the learners to engage more deeply with the contextual tools in ways that could allow them to increase their participation level in the relevant discourse. This raises concerns about the extent to which ML can achieve the intended outcomes.