Schools are adopting tablet computers at a rapid rate. Yet, the effectiveness of tablet computers as learning tools for young children has not been tested. In the present study, children (n = 36) from Kindergarten, Grade 1, and Grade 2 used 3 mathematics learning applications on 1 of 4 tablet computers and completed working memory and attention tasks. Ability to successfully use the tablet, engagement with each application, and the purposefulness of the interaction were measured. The goal is to model child-computer interaction so that both the cognitive ability of the child and the affordance and limitations of tablet computers are considered.