-57% is the change from 500 to 215
Calculation steps:
[( 215 - 500 ) ÷ 500] x 100 = -57%
Formula
Percentage change = [(215 - 500) / 500] x 100
Subtract the new number by the original number
215 - 500 = -285
-285 ÷ 500 = -0.57
-0.57 x 100 = -57%
Example