It has long been thought that there are gender differences in math ability. Boys get it, girls don't. However, research is beginning to shed new light on some old sets of data. Girls might just have the same ability as boys do for learning mathematical concepts. When women have equity and are well educated, their children (both genders) succeed in math. So then, when a gender gap exists, it may well be that it is due to sociocultural factors that differ among countries. See Science Daily for the study that debunks the myths about gender gaps in math.
See also: Math Anxiety Be Gone!