The hardest problem on the hardest test
27:26
This open problem taught me what topology is
16:03
The unexpectedly hard windmill question (2011 IMO, Q2)
17:14
the 5 hardest exams in the world
18:49
How to lie using visual proofs
14:03
Animation vs. Math
10:45
The Man Who Solved the $1 Million Math Problem...Then Disappeared
29:42
Why 4d geometry makes me sad
17:08