Is not that men are better in Math; is just depends on different situations
1) passed on from generations...how can I explain? Have you noticed how more men drive a cab? The first know mathematicians were men, whether in India, middle east and so on.
2) Ever seen how a shark can easily see if you are ready to be eaten? Men from long time ago learned to act quickly and the thought was quicker; women usually tended to follow their directions in order to survive.
3) Due to advances in science and life itself, is becoming 50/50 in the action-reaction needed to succeed in Math and other related subjects
4) Due to a difference in the brain..achieved from all said before: genetics and socialization, men still have that edge that makes you ask the question.