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 employed an alternating treatments design to compare the effects of two types of practice conditions on the subtraction fact fluency in a fifth-grade classroom. Eight, fifth-grade students participated in the study over a 5-week intervention period practicing addition and subtraction facts in a "fact families" condition (A +…

The contributions of domain-general abilities and domain-specific knowledge to subsequent mathematics achievement were longitudinally assessed (n = 167) through 8th grade. First grade intelligence and working memory and prior grade reading achievement indexed domain-general effects, and domain-specific effects were indexed by prior grade…