A decade has passed since the introduction of free primary education in the year 2000 in Lesotho. Studies such as the Needs Analysis (Lesotho College of Education, 2006) that were carried out in order to inform the Ministry of Education and Training about progress made in the teaching of core subjects in schools during the decade of free primary education reveal that there are multiple problems associated with the teaching of primary school mathematics. The reality of overcrowded classrooms impinges on the effective teaching of mathematics. Overcrowding is a generic problem facing many schools in Lesotho. However, other problems are both content and pedagogically oriented. Learning to teach mathematics is a complex process. It involves among other things, gaining Pedagogical Content Knowledge (PCK) (Shulman, 1986). The purpose of this study is to explore prospective elementary teachers’ understanding and use of mathematical representations. By mathematical representations I refer to instructional resources, through which teachers make mathematics comprehensible to learners. The three modes of representation (enactive, iconic, and symbolic) provide contexts for both learners and their teacher(s) to construct, negotiate, and re-construct meaning for mathematical concepts, procedures, and processes. The choice and use of representations is a key component of teachers’ PCK. This study is designed in four distinct tiers, spread over three years, to explore the development of understanding and use of mathematical representations for teaching, by a group of prospective elementary teachers in Lesotho. The main analytical framework was the Knowledge Quartet (KQ) (Rowland, Huckstep and Thwaites, 2005). The findings indicate that participants’ mathematical knowledge (foundation) influences their choice of representations and their use in instruction. I found that participants with strong mathematical knowledge are able to choose appropriate representations and are also able to use them effectively. It is recommended that for the improvement of mathematics teaching in Lesotho, the KQ be incorporated into mathematics courses studied by prospective elementary teachers at Lesotho College of Education. The model will assist student teachers to learn to plan and teach mathematics topics collaboratively, and therefore act as a tool for teacher development.