Whenever we get our cross country bibs for our races (the tags with the numbers on it), we do the exact same thing, trying to see if there's an equation out of the numbers. This should come naturally to me.
That... actually wasn't the equation I was looking for. The one I had was 1 / 4 = (5 - 3) / 8, but I guess I should have made sure there were no other combinations beforehand.