99.22% is the change from 256 to 510
Calculation steps:
[( 510 - 256 ) ÷ 256] x 100 = 99.22%
Formula
Percentage change = [(510 - 256) / 256] x 100
Subtract the new number by the original number
510 - 256 = 254
254 ÷ 256 = 0.9921875
0.9921875 x 100 = 99.22%