The relation to operands (RO) principles describe the relation between operands and answers in arithmetic problems (e.g., the sum is always larger than its positive addends). Despite being a fundamental property of arithmetic, its empirical relation with arithmetic/algebraic problem solving has seldom been investigated. The current longitudinal…

This study examined relations of affinity for solitude with social-behavioral, academic, and psychological adjustment in Chinese children and adolescents. The participants included 3,417 students (1,714 boys) in fourth, sixth, and eighth grades (M[subscript ages] = 10, 12, and 14 years, respectively) in China. Data on affinity for solitude were…

The purpose of this study was to examine child-level pathways in development of prealgebraic knowledge versus word-problem solving, while evaluating the contribution of calculation accuracy and fluency as mediators of foundational skills/processes. Children (n = 962; mean 7.60 years) were assessed on general cognitive processes and early…

Recent studies reveal that children can solve proportional reasoning problems presented with continuous amounts that enable intuitive strategies by around 6 years of age but have difficulties with problems presented with discrete units that tend to elicit explicit count-and-match strategies until at least 10 years of age. The current study tests…

How children and youth deal with academic challenges and setbacks can make a material difference to their learning and school success. Hence, it is important to investigate the factors that allow students to cope constructively. A process model focused on students' motivational resources was used to frame a study examining whether engagement in…

The present longitudinal study examined how relationships with teachers and peers jointly shape the development of children's behavioral engagement in late elementary school. A sample of 586 children (46% boys; M[subscript age] = 9.26 years at Wave 1) was followed throughout Grades 4, 5, and 6. A multidimensional approach was adopted,…

Using a sample of 767 children (403 girls, 364 boys), this study aimed to (a) identify groups with distinct trajectories of peer victimization over a 6-year period from primary school through the transition to secondary school, and (b) examine the associated personal (i.e., aggression or internalizing problems) and familial (family status,…

The study's goal was to identify the beginning of 1st grade quantitative competencies that predict mathematics achievement start point and growth through 5th grade. Measures of number, counting, and arithmetic competencies were administered in early 1st grade and used to predict mathematics achievement through 5th (n = 177), while controlling for…

Previous studies have found that children have difficulty solving proportional reasoning problems involving discrete units until 10 to 12 years of age, but can solve parallel problems involving continuous quantities by 6 years of age. The present studies examine where children go wrong in processing proportions that involve discrete quantities. A…

The transition to middle school is often marked by decreased academic achievement and increased emotional stress, and African American children exposed to social risk may be especially vulnerable during this transition. To identify mediators and protective factors, the authors related severity and timing of risk exposure to academic achievement…