-3% is the change from 500 to 485
Calculation steps:
[( 485 - 500 ) ÷ 500] x 100 = -3%
Formula
Percentage change = [(485 - 500) / 500] x 100
Subtract the new number by the original number
485 - 500 = -15
-15 ÷ 500 = -0.03
-0.03 x 100 = -3%
Example