This paper examines the factors that hinder students' success in working with and understanding the mathematics of quadratic equations using a case study analysis of student error patterns. Twenty-five Year 11 students were administered a written test to examine their understanding of concepts and procedures associated with this topic. The findings indicate that students' success was inhibited by errors that arose from a lack of procedural understanding regarding fractions, algebraic processes, and conceptual understanding regarding algebraic conventions. Without this prerequisite knowledge, working with and understanding the nature of quadratics was hindered.