The choice to avoid math courses can have lifelong repercussions (Sells, 1980). The selection of high school mathematics courses can act as a filter, effectively barring female and ethnic minority students from many professions. For example, if a student has only two years of high school math, that student cannot take calculus as a freshman in college, which thereby eliminates some college majors and filters some students out of those majors and out of careers requiring those majors.