This study discusses the nature of mathematics and analyses current trends in mathematics education which focus on the learning process and its inter-relationship with the social and other contexts in which it occurs. In particular, the notion is presented that the development of mathematical understanding cannot be separated from the situation which nurtures it. The study relates these notions to the specific educational characteristics of students who are deaf or hard of hearing in relation to the development of understanding in mathematics education. The particular educational focus of this study is the development of the concept of fractions with a group of four eleven and twelve year-old students who attend a special education unit for students who are deaf or hard of hearing. These students comprised half of the Year 6 and 7 classes in the unit at the time. The other students attended a regular hearing class for their mathematics instruction, but it had been determined that the students in the research project required an alternative program in mathematics. The approach implemented in this study was a departure from traditional techniques for teaching fractions and relied extensively on the use of games with almost no formal instruction. It emphasised the development of appropriate language to facilitate an understanding of the notion of fractions through the investigation of concrete materials, pictorial representations and interactions between students and teacher. The approach had previously been used in a research project with hearing students and been found to develop an understanding of fractions. Each of the students is described and evidence of his/her participation is provided. The program is detailed through a sequence of games and activities and student outcomes. The specific role of games receives special attention in terms of mathematical and social outcomes. Implications are drawn for approaches to developing understanding of fractions and mathematics generally for students who are deaf or hard of hearing which focus on the relationship between developing understanding and the language to describe that understanding. If there is to be an across the board improvement in 'quantitative literacy' (Daniele, 1993) for students who are deaf or hard of hearing, it is suggested that sweeping changes are required at school level. This research provides a starting point for discussion among professionals as to their beliefs about mathematics, their expectations of their students and how best to approach the serious deficit of true understanding of mathematics among students who are deaf or hard of hearing.