Yet another example of why I don't take anything involving numbers within the books seriously and instead go by my own personal headcannon for all things math related.

Seriously, did Rowling even try to get the math right. I mean, I get being bad at math but this is just ridiculous.

 

J.K. Rowling is not an intelligent person.

She is the same author who said that Lucius Malfoy avoided Azkaban after the Second War.

Pure delusion.

 

I think J.K. Rowling revised things as she went along. Some aspects of the universe wouldn't have needed to be pinned down when writing The Philosopher's Stone.

There is certainly an element of magic in all of it. I do feel as well that the notion of magic is used sometimes as a crutch or an excuse for lack of logic or reason.

However, we need to accept a certain degree of magic - including the inexplicable logic escapes, as it adds to the world. It adds a sense that anything is possible, and that wizarding society is wacky and sometimes without reason.

On another note, Dumbledore is an exceptional individual in many ways, so his magic and magic in general could potentially explain his mobility and health.