The study reported in this paper was conducted to examine four South African grades 7 teachers' understanding of the importance of instructional time as a teaching resource to develop learners' relational understanding in mathematics. A constructivist philosophical approach, document analysis, lesson observations and interviews were used to collect data. The findings indicate that the four teachers faced, to varying degrees, challenges in using instructional time as expected. Two did not help learners understand the relationship between the concepts taught and the examples selected to scaffold learning. They prioritised drawing learners' attention to correct responses to questions posed. Only two teachers used strategies that encouraged the learners to share experience, collectively reflect on individual taken-for granted conceptions, probe and identify how they could be used to explain mathematical concepts. The conclusion is that the teachers' lack of understanding the pedagogical significance of instructional time as social time highlighted inadequate curriculum and subject content expertise and supported the general concern about the quality of mathematics teaching within the country.