If you're referring to this example, the numbers were chosen arbitrarily.
King - Man + Woman = Queen
[5,3] - [2,1] + [3, 2] = [6,4]
The purpose was to show that if you had a 2 dimensional embedding space for the words, King, Man, Woman and Queen. Upon doing some simple arithmetic, you would see that the position of the words King and Queen are very close to each other. Furthermore, you can conclude that King and Queen are close to each other when subtracting Man from King and adding Woman (which could be an oversimplified definition of Queen).
I will add this note and a visual into the article momentarily, hope this helps.