7. Jia Xian Made Math Class More Difficult Forever
Jia Xian grew up as an apprentice under the mathematician named Chu Yan. When he grew up, he continued to be the mathematic scholar and lived and worked in the royal palace during the Song Dynasty. Like other royal employees, he was forced to become a eunuch, but it helped him to not get distracted him his academic work. Basically, he was like a resident genius, which was customary for the time. Making academic breakthroughs would help the empire make waves in the history books.
He was able to make some huge breakthroughs in mathematics that we still use today, like the square root, and the additive-multiplicative method. He published multiple mathematics textbooks. No one knows what Jia Xian looks like, and there are no portraits of him that exist. But his math is still left behind as his legacy. However, few people ever remember who Jia Xian is, or ever give him credit for the work he devoted his life to.