Mathematician #9 is Jaime Escalante, a math teacher famous for his work with under-served students at a Los Angeles high school. Escalante challenged the administration and worked to develop a math program that made it possible for students to achieve high levels of mathematics, pass the AP Calculus exam, and enroll in prestigious colleges.
Escalante was popularized in the 1988 movie Stand and Deliver, which he describes as 90% truth and 10% drama. After he retired, he remained active in education, and I found this interview with Education Week very informative and interesting. In 2016 the United States Postal Service honored Escalante by issuing a commemorative stamp.