|Helen Chick - Vol. 29 Num. 3 (2009)|
|Choice and use of examples as a window on mathematical knowledge for teaching||26-30|
Examples play a central role in mathematics learning and teaching. Although they involve specific situations, their purpose is to exemplify more general mathematical principles. A critical task of teaching, therefore, is to choose appropriate examples and implement them in pedagogically productive ways. This study considers the examples used by two teachers working with the topic of ratio and provides insight into mathematical knowledge for teaching. Critical to such a study is the issue of what an example can “afford” or offer in terms of illustrative power. Examining affordances highlights that constructing examples that illustrate general principles successfully is specialised content knowledge.