Emily Wells

This chapter describes the four main sources of individual differences in arithmetic that have been identified through research with children and adults. Numerical quantitative knowledge invokes basic cognitive processes that are either numerically specific or are recruited to be used in quantitative tasks. Attentional skills, including executive attention and various aspects of working memory are important, especially for more complex procedures. Linguistic knowledge is used within arithmetic to learn number system rules and structures, specific number words, and in developing and executing counting processes. Strategic abilities, which may reflect general planning and awareness skills, are involved in selecting procedures and solving problems adaptively. Other important sources of individual differences include automaticity of knowledge related to practice, experiences outside school, and the specific language spoken. Suggestions are made for further research that would be helpful in establishing a full picture of individual differences in arithmetic.