Take 'em out of the equation: Student understandings of 'cancelling'

Abstract

Questioning during interviews with students about their responses to a set of algebra test items revealed a range of understandings of the concept of cancelling. Although most students could apply a 'cancelling' procedure, their explanations revealed a very limited understanding of when to cancel, often coupled with a false use of the concept to include negation of one term by another. This paper discusses some examples that illustrate how students understand the procedure of cancelling and the meanings they ascribe to it.