The fact that a stereotype isn't always negative like the men reminded of their supposed advantage in math should do better than men not reminded of this. The other possibility is, as we have broached, a stereotype threat effect where the group for whom the stereotype is derogatory performs more poorly, as would be expected from women reminded of the presumed male advantage in math. this inflates a fake image one can have to a sex and create a very offensive view throughout the society.  


https://www.psychologytoday.com/us/blog/perceptual-asymmetries/201602/when-stereotypes-affect-our-thinking