-0.4% is the change from 500 to 498
Calculation steps:
[( 498 - 500 ) ÷ 500] x 100 = -0.4%
Formula
Percentage change = [(498 - 500) / 500] x 100
Subtract the new number by the original number
498 - 500 = -2
-2 ÷ 500 = -0.004
-0.004 x 100 = -0.4%
Example