A meta-analysis of 242 articles assessing the math skills of 1,286,350 people found no difference between the two sexes. This was confirmed in an analysis of the data from several large surveys of American adolescents (the National Longitudinal Surveys of Youth, the National Education Longitudinal Study of 1988, the Longitudinal Study of American Youth, and the National Assessment of Educational Progress).
(2010). New trends in gender and mathematics performance: A meta-analysis..
Psychological Bulletin. 136(6), 1123 - 1135.