students in nationally representative sample of US
students, when controlling for fluid and crystallized intelligence, short-term memory,
and processing speed. As hypothesized, structural equation modeling comparing elementary
school students and middle and high school students revealed that long-term
retrieval skills became a better predictor of both mathematics calculation and mathematics
problem solving as age and grade increased. Future research should focus on the
effectiveness of interventions to improve long-term retrieval skills in general, and
arithmetic facts retrieval and problem solving procedures in particular, at all grades,
including high school.