51.56% is the change from 256 to 388
Calculation steps:
[( 388 - 256 ) ÷ 256] x 100 = 51.56%
Formula
Percentage change = [(388 - 256) / 256] x 100
Subtract the new number by the original number
388 - 256 = 132
132 ÷ 256 = 0.515625
0.515625 x 100 = 51.56%