66500% is the change from 1 to 666
Calculation steps:
[( 666 - 1 ) ÷ 1] x 100 = 66500%
Formula
Percentage change = [(666 - 1) / 1] x 100
Subtract the new number by the original number
666 - 1 = 665
665 ÷ 1 = 665
665 x 100 = 66500%
Example