This is one of my favorite videos on YouTube. Vi (Victoria) Hart teaches all about Fibonaccci numbers, and how they occur in nature, particular with pine cones, spirals, and snails. The creator calls herself a “recreational mathemusician”. She has even had articles written about her in the New York Times.
This video is an excellent example of “stop motion”, where dozens or hundreds if time separated video shots are taken (or where the video is edited to remove the boring intervening parts). It’s also a great example of a type of “Doodle Video”, but this one is done with a real hand on a school notebook (unlike the fake Doodle videos where graphics are pretended to be drawn by a mysterious fake hand).
The video also offers extremely clever and entertaining narration that was carefully timed and spliced to match the video. We never even see Vi in the entire video, only her hand.