[1] As of 2017, he is on leave from his faculty position as Assistant Professor of Mathematics and Statistics Education at the University of San Francisco.
[2] Alexander grew up in Charlotte, North Carolina, and has worked as a teacher in Harlem.
[3][4] In college, he worked as a teaching assistant in mathematics, as well as with the Upward Bound program.
[5] Alexander obtained his bachelor's degree at University of North Carolina at Chapel Hill in 2007, where he double majored in mathematics and sociology, and his MA in teaching mathematics at New York University.
He earned his MS, MPhil, and PhD in mathematics and education at Columbia University,[6] graduating in 2015 under the supervision of Erica N.