-2% is the change from 500 to 490
Calculation steps:
[( 490 - 500 ) ÷ 500] x 100 = -2%
Formula
Percentage change = [(490 - 500) / 500] x 100
Subtract the new number by the original number
490 - 500 = -10
-10 ÷ 500 = -0.02
-0.02 x 100 = -2%
Example