A couple of interesting studies have indicated the influence of gender on choice. The choices weren't about math, but demonstrate physiological influences nonetheless.
One is Alexander's research. An excerpt from an article found
here says, "It’s commonly believed that boys and girls learn what types of toys they should like based solely on society’s expectations, but psychologist Gerianne Alexander’s work with vervet monkeys is challenging that notion.
Alexander, whose research focuses on sex differences in behavior and the biological factors that influence them, examined the monkeys as they interacted with toys. She and her collaborator, Melissa Hines of the University of London, found that the monkeys’ toy preferences were consistent along gender lines with those of human children. The study was published earlier this year in "Evolution and Human Behavior."
Though the monkeys had no concept of a "boy" toy and a "girl" toy, they still showed the same gender preferences in playing with the toys, Alexander says. That is, compared to female monkeys, male monkeys spent more time with "boy" toys, and the female monkeys, compared to their male counterparts, spent more time with "girl" toys, she notes."
Another study connects hormones to toy choices. An excerpt from an article found http://www.findarticles.com/p/articles/mi_m2372/is_1_41/ai_n6032943 says, "The strongest evidence of hormonal influences on human behavioral development has come from studies of childhood play. Girls with the genetic disorder congenital adrenal hyperplasia (CAH) are exposed to high levels of androgen prenatally (Pang et al., 1980; Wudy, Dorr, Solleder, Djalali, & Homoki, 1999). . . . Despite postnatal treatment, girls with CAH show altered play behavior (see Hines, 2002, 2004, for reviews). They are more likely than other girls to prefer toys that are normally preferred by boys (e.g., cars) and less likely to prefer toys that are normally preferred by girls (e.g., dolls). They also show increased preferences for boys as playmates and for boy-typical activities. These differences in play behavior are seen on questionnaires, in interviews, and in direct observation of toy choices. They also are seen when girls with CAH are compared to unaffected female relatives, as well as to controls matched for background factors like age and parental socioeconomic status. Similar outcomes have been seen for girls exposed to high levels of androgenic hormones prenatally because their mothers were prescribed hormones during pregnancy (Ehrhardt & Money, 1967). In addition, normal variability in maternal testosterone levels during pregnancy has been found to relate positively to male-typical play behavior in female offspring at the age of 3 1/2 years (Hines et al., 2002a)."
That's why it is 50/50.