Evolution of cognitive processes for solving simple additions during the first three school years

The development of a group of children's cognitive strategies forn solving simple additions was studied by analyzing verbal reports given after each problem (I+J) was solved. The evolution of the cognitive processes involved a gradual shift from more primitive and less demanding strategies (in which, e.g., the child's fingers served as memory aid) to reconstructive memory processes (in which e.g., the answer was derived in a counting process in working memory) to retrieval processes (in which the answer was obtained form long term memory search). During the first semester of the first school year 36 percent of the problems (I + J≤13, I≠J, I≠0, I≠1, J≠1,) could not be answered, 40 percent of the solutions were obtained in the most frequent processes utilizing external meory aid and 16 percent in reconstructive memory processes. When in the second semester of the third school year, the same children solved th same problems by utilixing the followitn most frequent strategies; 31 percent long term memory retrieval, 38 percent reconstructive memory processes and 19 percent in processes utilizing external memory aid. If a problem was solved by using a given strategy this strategy was often most likely to have been used bt the child on the occasion before and to be used during the following semester as well. For long‐term memory solutions this tendency was strongest and for other strategies it was coupled with a gradual shift towards strategies with increasing sophistication in terms of memory representation.