Youths' development can be positively or negatively impacted by various factors in their internal and external environment. This study investigated the interactive effects of self-regulation and internalizing and externalizing problems on academic achievement (reading and maths) and positive youth development (PYD) across one year. Data were…

This chapter situates fraction learning within the integrated theory of numerical development. We argue that the understanding of numerical magnitudes for whole numbers as well as for fractions is critical to fraction learning in particular and mathematics achievement more generally. Results from the Delaware Longitudinal Study, which examined…