-48.8% is the change from 500 to 256
Calculation steps:
[( 256 - 500 ) ÷ 500] x 100 = -48.8%
Formula
Percentage change = [(256 - 500) / 500] x 100
Subtract the new number by the original number
256 - 500 = -244
-244 ÷ 500 = -0.488
-0.488 x 100 = -48.8%