Fraction arithmetic facility is fundamental to learning more advanced math topics. However, attaining the ability to add and subtract fractions is hard for many students. The present longitudinal study examined students' growth on simple addition and subtraction word problems between fourth and sixth grades (N = 536). Latent class growth analyses…

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…

Two studies involving 110 and 91 children aged 5 to 7 years show that children's knowledge of counting and addition facilitated their acquisition of a concept not taught in school, that every number has a natural successor (Successor Principle). Even the oldest children could not rank order correctly numbers that contained fractional notations.…