The number line estimation task is frequently used to measure children's numerical magnitude understanding. It is unclear whether the resulting straight, horizontal, left-to-right-oriented estimate patterns indicate task constraints or children's intuitive number--space mapping. Three- to six-year-old children (N = 72, M[subscript age] = 4.89, 56%…

This research investigated whether delayed school entry was associated with higher achievement in national tests of reading and numeracy in Grades 3, 5, 7, and 9 (n = 2,823). Delayed entry was related to advantages in reading (0.14 SD) and numeracy (0.08 SD) at Grade 3, although little variance was explained (1%-2%). This slight advantage…

Place value notation is essential to mathematics learning. This study examined young children's (4-to 6-year-olds, N = 172) understanding of place value prior to explicit schooling by asking them write spoken numbers (e.g., "six hundred and forty-two"). Children's attempts often consisted of "expansions" in which the proper…

Executive control (EC) is related to mathematics performance in middle childhood. However, little is known regarding how EC and informal numeracy differentially support mathematics skill acquisition in preschoolers. A sample of preschoolers (115 girls, 113 boys), stratified by social risk, completed an EC task battery at 3 years, informal numeracy…

Two experiments examined kindergartners', first graders', and second graders' numerical estimation, the internal representations that gave rise to the estimates, and the general hypothesis that developmental sequences within a domain tend to repeat themselves in new contexts. Development of estimation in this age range on 0-to-100 number lines…