ABSTRACT
The mathematics of the Piagetian cognitive structures is rarely analysed in detail. * In the following two chapters a number of cases are taken in order to examine the particular forms of these cognitive structures during the periods of 'middle childhood' and adolescence. Cognitive structure in the Piagetian sense essentially means the organisation of mental operations. It is not the thoughts themselves but the activity of thinking that is said to be organised into such structures. Putting objects and classes into order, relating them, seeing correspondences, all these are said to be forms of cognitive structuration.
