Find a good laugh in 40 minutes of the YouTube about people in the old days do not have -ve no. and 0. Also, the surprise way to do algebra by geometry is fun.

Find a good laugh in 40 minutes of the YouTube about people in the old days do not have -ve no. and 0. Also, the surprise way to do algebra by geometry is fun. Studying pre-socrates at the moment and there is a speculation whether the "unbounded" guy is also a geometric guy.