explores the various uses and aspects of symbols in school mathematics and also examines the notion of mathematical meaning. It is concerned with the power of language which enables us to do mathematics, giving us the ability to name and rename, to transform names and to use names and descriptions to conjure, communicate and control our images. It is in the interplay between language, image and object that mathematics is created and can be communicated to others. The book also addresses a set of questions of particular relevance to the last decade of the twentieth century, which arise due to the proliferation of machines offering mathematical functioning.