When studying aims and programs for elementary schools historically, we find that knowledge and skills have been among the dominating factors in the elementary school curriculum throughout the last century. The terms knowledge and skills usually are defined as basic skills which children are supposed to learn at school. In the USA, the basic skills also have been called the three R's, synonymous with arithmetic, reading, and writing. Because competence in the basic skills is a prerequisite for knowledge acquisition of other school subjects, e.g. science, history, etc, it is important that the...