When a sample of academically talented students in Grades 2-6 was given a test of mathematical reasoning ability, boys performed better overall than girls. The gender differences for mathematical ability appeared as early as 2nd grade in samples tested over a 7-year period but varied somewhat according to mathematical subskills. There were no substantial gender-related differences on tasks requiring students to identify whether enough information was provided to solve a task; however, boys performed better than girls on tasks requiring application of algebraic rules or algorithms, as well as on tasks in which the understanding of mathematical concepts and number relationships was required.