Mathematicians and their blackboards

Colorful Blackboard - Placement Exam

Interesting insight is found in a New York Times article, published September 23, 2019, that explores the significance of the blackboard to many renowned mathematicians.  Stanford’s own, Professor Tadashi Tokieda has input (in his typical whimsical style) in this examination.  You can see Professor Tokieda’s offering half-way down the article, "Where Theory Meets Chalk, Dust Flies"