In earlier research the writer was constrained by the variables which were continuously appearing in both experimental class teaching experiences and various psychological experiments to distinguish four levels of cognitive sophistication in so far as mathematical material was concerned between the ages of 7 years and 17 years. In current research…

Findings from five related studies carried out in Tasmania, Australia in 1979-80 are summarized. The first study attempted to determine the memory capacity of a cross-sectional population of children aged 4-7, while the second study was designed to portray differences on a variety of mathematically related developmental tasks for the same…