I am a Colombian, British trained (University of Warwick) mathematician. I have taught (and still teach) students of all ages, from preschool to university. My main interests are in number theory and graph theory, and where the two meet. Brought up reading Martin Gardner, I am a great believer in the power of recreational mathematics to liven up our teaching. I am the author of *The Bogotá Puzzles*, Dover, 2020.

I can be reached at [email protected].