[foo101]

Ramanujan also claimed 1 + 2 + 3 + ... = -1/12.

How does that work? Who can explain this to me?

[asfarley]

I think this is basically a “shock value” interpretation of a more subtle statement. Obviously adding strictly-positive numbers does not result in a negative number under normal arithmetic. Check the numberphile video and you may be simultaneously irritated and disappointed.

[stan_rogers]

Burkard Polster's (Mathologer) videos on the subject are probably going to be more useful than Numberphile. Numberphile merely presents a trick; Mathologer points out both that it's patent nonsense [0] and that it's useful patent nonsense [1].

[0] https://www.youtube.com/watch?v=YuIIjLr6vUA [1] https://www.youtube.com/watch?v=jcKRGpMiVTw

[adenadel]

Here's a Numberphile video on this

https://www.youtube.com/watch?v=w-I6XTVZXww