-30.47% is the change from 256 to 178
Calculation steps:
[( 178 - 256 ) ÷ 256] x 100 = -30.47%
Formula
Percentage change = [(178 - 256) / 256] x 100
Subtract the new number by the original number
178 - 256 = -78
-78 ÷ 256 = -0.3046875
-0.3046875 x 100 = -30.47%