-91.02% is the change from 256 to 23
Calculation steps:
[( 23 - 256 ) ÷ 256] x 100 = -91.02%
Formula
Percentage change = [(23 - 256) / 256] x 100
Subtract the new number by the original number
23 - 256 = -233
-233 ÷ 256 = -0.91015625
-0.91015625 x 100 = -91.02%