One of the classic and much-studied cases of knowledge growth is the acquisition of the addition table. Children at one point know their addition facts, but can solve addition problems by repeated counting because they know how to count. Repeated counting is one way to learn the addition facts and it is believed that at least some children learn their addition tables by storing the results of repeated counting (Siegler, 1987; Zbrodoff, 1979). Chapter 9 on Cognitive Arithmetic will pursue modeling this transition in great detail and this chapter will describe a related problem. Here we would like to describe it briefly as an example of learning goal chunks.

ACT-R Model