Exactly. I was never good at maths, and that, I hadn't the first clue what it was. It's like asking you to translate this.



You can never go wrong with maths.


<Snipped quote by KabenSaal>
That's actually a misconception propagated by Supernatural. salt has never had any form of supernatural repelling qualities.
In ancient Jerusalem (as well as other desert areas) salt was used to purify and preserve meat. Because of how fast meat spoiled in desert countries you needed salt unless you were going to butcher and eat the animal immediately. This caused salt to become a symbol of purity and life in many ancient cultures because food was life and salt was necessary to preserve it.
Supernatural took this a step further by saying that since it was a symbol of purity demons, unclean as they are could not abide it and as a symbol of life ghosts being without life could not tolerate it. Before Supernatural salt had no demon slaying or ghost banishing qualities.
Shockingly high sodium chloride concentrations scattered about after them combat matches