Number-comparison learning by children classified as mentally retarded

A training experiment was undertaken to determine whether children classified as mentally retarded could learn a general magnitude-comparison rule ("The number that comes after another in the number sequence is more than the preceding number"). After a pretest, 22 subjects were randomly assigned to an experimental or a control training group. On both immediate and delayed posttests, the experimental subjects significantly outperformed control children on trained number pairs. A modest amount of transfer was also evident. The results suggest that a counting-based approach that utilizes rule rehearsal can help children classified as mentally retarded to use their representation of the number sequence to make mental magnitude comparisons.