ABSTRACT
There are many reasons why people make mathematical errors. Sometimes mistakes are made through the slip of a pen or a moment of inattention never to be made again. Other times errors occur as a result of a slight misunderstanding or a lack of knowledge which is shortly to be attained and other times mistakes are the result of more fundamental misconceptions which are often difficult to unearth and which can take years to rectify. Some of these errors can be predicted; others cannot. Some are useful (see below); others are not.
