Well, this irrational, or never-ending, ratio starting with 1.618 has been given many names over the years including the “golden ratio” and the “divine proportion”.
if you have a vertical line with 0 in the middle, the number above zero will be positive numbers That will be above sea level. The number below the zero will be negative numbers which are below sea level.
so the 2.5 below sea level will be in the negative side (below the zero) between -2 and -3.