Why does my math class have so few girls?

Why does my math class have so few girls? Why did the engineering department here have only one female professor last year? These are the types of questions many girls in S.T.E.M. at Swat tend to ask ourselves. Issues of underrepresentation of women in S.T.E.M. fields don’t start at Swat. By the time students arrive here, they have already been influenced by these disciplines’ implicit and explicit biases. It is the presence of such biases, most of which begin to heighten during middle and high school, that is constantly deterring women from pursuing computational fields, and it is imperative that institutions begin to tackle these biases head on.
In high schools across the United States, boys are dominating the higher-level classes in fields of math and applied mathematics.  Approximately 2.1 million girls and only 1.75 million boys took A.P. exams in varying subjects in 2013; however, in A.P. exams in fields of math and applied mathematics, boys outnumbered girls by strikingly large margins. Despite the fact that girls take a significantly greater percentage of all A.P. exams, boys still take more exams in all S.T.E.M.-related fields. The fact that more boys are taking these exams indicates that boys outnumber girls by a large margin in A.P. classes — high school classes usually at the highest level in any given subject — concerning S.T.E.M.-related fields.
Taking these A.P. classes in a subject will naturally increase the likelihood that a student will major in that subject in college. While some math majors at Swat do start in Math 15, it is far easier to complete the major if they come in with A.P. credit, and a student will naturally gravitate towards subjects in which they feel they possess more confidence and ability.
One of the main reasons many of the speakers cited that is keeping women out of the profession are the implicit biases — negative mental attitudes towards a group that people hold at an unconscious level.  Teachers perpetuate these biases unconsciously while teaching, and they will often go unnoticed by all until they are brought to attention. A student’s subconscious will pick up things that they do not actually know they are internalizing.  
With both information and experience in mind, I have compiled a list of suggestions for improving the ways in which institutions treat women. All schools and universities should ensure that they have 50 percent female teachers in mathematics and fields such as physics and economics which require the application of mathematics. All standardized testing involving mathematics and fields of applied mathematics must not permit test-takers to bubble in their gender until after they have already taken the test.
All students should be told two statements at the beginning of their middle school careers. The first is that brains are as malleable as plastic, and anyone has the ability to learn anything regardless of their race, class, or gender. The second is that gender plays no role in the ability for a child to learn any subject, and that the stereotypes surrounding the idea that boys are naturally better at math are 100 percent false.  
For every famous male mathematician a teacher mentions in class, teachers must also mention a female mathematician. I have heard my math teachers for years go on and on about men such as Euler, Pythagoras, and Taylor.  I have never been in a math class where the teacher mentioned the name of a famous female mathematician. Though the discoveries of the men listed above may be more relevant to the lesson than the discoveries of Hypata or Maryam Mirzakhani — the first woman to win the Fields Medal — only mentioning male names sends the message to the subconscious of females that women are lacking something instrumental to the possession of a great mathematical mind.  Simply mentioning a brilliant female mathematician will help derail this implicit bias. Elementary, middle, and high schools should have posters up in their hallways and classrooms of brilliant women in mathematics as role models for students.
Teachers and school administrators in math and fields of applied mathematics must do the following: read literature on the implicit biases that work against girls in their fields.  They must be aware of these biases so as never to reproduce or ignite them. For example, a teacher should never make the statement, “girls think differently,” or “girls show their skills in different ways.”
A teacher or professor must never say the following statements to a girl studying math: “I do not understand why you are not getting this.” “You are not good at conceptual math.” “You just don’t have the intuition.” Math teachers must never attribute the success of one student to “natural ability” while attributing the success of another to “hard work,” as that distinction implicitly conveys a distinction between the two students even if they are performing at the same level.
Finally, I believe that it is critical for teachers and professors to emphasize that natural talent, whether or not male students have it inherently, is not necessary in order for a student to excel at mathematics.
Swat, for the most part, does a better job than my high school did at trying to defuse some of the already ingrained biases against women in S.T.E.M. fields. My Linear Algebra professor freshman year did an excellent job with this, emphasizing to the entire class from day one that just because people don’t look like you in this field doesn’t mean you shouldn’t pursue it. I am not arguing that female S.T.E.M. students need their hands held or to be told they can do it, I am simply advocating for the ability to work in a slightly less bias-ridden environment. As a Computer Science and English double major, I do not even know which field I would like to pursue after college.  I simply want the ability for girls to choose math to exist untainted by harmful societal perceptions, biases, and stereotypes.
With the changes proposed above, girls will not have to walk into a math class and feel inhibited by their gender, and I believe that every student deserves to walk into a math class without feeling like they are at a disadvantage before they even begin to solve problems.  Removing implicit biases, stereotype threat, and media influences that keep girls out of mathematics will result in more girls in the higher level math classes in high schools, and subsequently, more girls with the ability to realize their potential in mathematics.
When constantly bombarded with the ubiquitous and pernicious images conveying a lack of intelligence surrounding their gender, young girls are socialized to believe that they are inferior intellectually, and thus incapable of tackling the hard problems.  We are severely limiting ourselves and our society based on perceptions created by the media and stereotypes perpetrated implicitly by teachers and institutions.