Japanese children's numerical competencies: age- and schooling-related influences on the development of number concepts and addition skills.

Using a cutoff design (J. Bisanz, F. J. Morrison, & M. Dunn, 1995) to separate school-related influences from those that are age related, the study investigated the development of number concepts and addition skills in Japanese children. Three groups of kindergarten and 1st grade children who differed in age and/or school experiences completed tasks on their numerical competencies 1 and 6 months after school entrance. Children's use of addition strategies, rather than their solution accuracy, changed primarily as a function of schooling, not age. Children's Base 10 number concepts improved with the amount of schooling, as well as with other social and age-related factors. Results suggest that schooling is an important determinant in developing Japanese-speaking children's numerical competencies, which were not explained solely by their language characteristics or by age-related factors.