This paper presents a meta-analysis of gender differences in mathematics performance, based on data from 242 studies published between 1990 and 2007, and large national data sets from U.S. adolescents over the past 20 years. The overall effect size was d = 0.05, indicating no significant gender difference in mathematics performance. Variance ratios ranged from 0.88 to 1.34, indicating nearly equal male and female variances. The analysis also found that gender differences in mathematics performance were small and varied depending on factors such as age and test difficulty. The results suggest that males and females perform similarly in mathematics. The study also found that gender differences in mathematics performance were not significant across different ethnic groups or nations. The magnitude of gender differences in mathematics performance has not declined significantly from 1990 to 2007. The study also found that males displayed slightly greater variance in scores, but the variance ratios were not far from 1.0, indicating equal variances. The findings suggest that stereotypes about gender and mathematics are not supported by the data, and that gender differences in mathematics performance are small and not consistently favoring one gender over the other. The study concludes that there is no significant gender difference in mathematics performance, and that the data do not support the idea that males are superior in mathematics. The results suggest that the gender gap in mathematics performance has narrowed over time, and that the data do not support the idea that males are more capable in mathematics than females. The study also found that the gender gap in mathematics performance is not significant across different ethnic groups or nations. The study concludes that there is no significant gender difference in mathematics performance, and that the data do not support the idea that males are superior in mathematics. The results suggest that the gender gap in mathematics performance has narrowed over time, and that the data do not support the idea that males are more capable in mathematics than females.This paper presents a meta-analysis of gender differences in mathematics performance, based on data from 242 studies published between 1990 and 2007, and large national data sets from U.S. adolescents over the past 20 years. The overall effect size was d = 0.05, indicating no significant gender difference in mathematics performance. Variance ratios ranged from 0.88 to 1.34, indicating nearly equal male and female variances. The analysis also found that gender differences in mathematics performance were small and varied depending on factors such as age and test difficulty. The results suggest that males and females perform similarly in mathematics. The study also found that gender differences in mathematics performance were not significant across different ethnic groups or nations. The magnitude of gender differences in mathematics performance has not declined significantly from 1990 to 2007. The study also found that males displayed slightly greater variance in scores, but the variance ratios were not far from 1.0, indicating equal variances. The findings suggest that stereotypes about gender and mathematics are not supported by the data, and that gender differences in mathematics performance are small and not consistently favoring one gender over the other. The study concludes that there is no significant gender difference in mathematics performance, and that the data do not support the idea that males are superior in mathematics. The results suggest that the gender gap in mathematics performance has narrowed over time, and that the data do not support the idea that males are more capable in mathematics than females. The study also found that the gender gap in mathematics performance is not significant across different ethnic groups or nations. The study concludes that there is no significant gender difference in mathematics performance, and that the data do not support the idea that males are superior in mathematics. The results suggest that the gender gap in mathematics performance has narrowed over time, and that the data do not support the idea that males are more capable in mathematics than females.