-22% is the change from 500 to 390
Calculation steps:
[( 390 - 500 ) ÷ 500] x 100 = -22%
Formula
Percentage change = [(390 - 500) / 500] x 100
Subtract the new number by the original number
390 - 500 = -110
-110 ÷ 500 = -0.22
-0.22 x 100 = -22%
Example