Klein and Bisanz (2000) sought to examine the poor performance of preschoolers on arithmetic problems. They wanted to determine the degree to which certain information-processing demands made certain problems more difficult than others to solve. Klein and Bisanz (2000) hypothesized that information-processing demand, particularly those that involved use of working memory, would cause the young children to struggle on some problems more than others. They began their study by gathering a sample of 48 4-year old children. Each child was presented with 2-term and 3-term nonverbal forms of arithmetic problems to examine their capabilities with addition and subtraction. The results of the study aligned with their original hypothesis. It revealed a negative correlation between the maximum number of units that need to be held in working memory and the children's overall ability to solve simple arithmetic problems. .
Alike Klein and Bisanz (2000), the extent to which working memory plays a role in young children's performance in demonstration the nonverbal task is a question which Huttenlocher, Jordan, and Levine (1994) too desired to uncover. Children have been shown to have success in solving simple arithmetic problems as early as 2 1/2 years of age. Research conducted by Hunttelocher et al. (1994) supported these claims as well. The authors wanted to determine whether or not young children had the ability to solve basic nonverbal calculations. They hypothesized that a young child's ability to calculate nonverbal calculations should appear around the age of 2-years old, and involve domain-general symbolic processes similar to those involved in symbolic play and the use of physical models. Huttenlocher et al (1994) tested this hypothesis through an experiment in which young children had to determine the amount of objects that were hidden inside an array after a certain number of objects had been added or removed from it.