3 outside the box problems from China
6:39
Nice geometry problem - area of rectangle?
12:11
When a genius misses an easy question
11:24
Singapore test question that left students crying
27:26
This open problem taught me what topology is
22:59
La paradoja de la cúpula: una laguna en las leyes de Newton
11:51
Find all real candidates for x
22:38
Cómo atrapar a un tramposo con matemáticas
13:46