Vedic math figured out how to multiply and divide large numbers 1000+ years ago. In the early 1900’s a fella who taught himself math was able to count to infinity...his answer -(1/12).
That answer shows up in quantum mechanics and string theory.
I don’t usually monkey around with Riemann zeta functions but...I do remember about Ramanujan and the taxicab number!
A much better explanation and fun too!
https://plus.maths.org/content/infinity-or-just-112
The trick
So how did the people in the Numberphile video “prove” that the natural numbers all add up to -1/12? The real answer is that they didn’t. Watching the video is like watching a magician and trying to spot them slipping the rabbit into the hat.