Curriculum movements in the United States and Australia, characterized by such documents as Curriculum and Evaluation Standards for School Mathematics(NCTM 1989) and A National Statement on Mathematics for Australian Schools (AEC 1991), have challenged the conventional view of algebra as formal structure, arguing that algebra is fundamentally the study of patterns and relationships. Increased emphasis has been given to developing an understanding of variables, expressions, and equations and to presenting informal methods of solving equations. The emphasis on symbol manipulation and on drill and practice in solving equations has decreased (NCTM 1989).