100.39% is the change from 256 to 513
Calculation steps:
[( 513 - 256 ) ÷ 256] x 100 = 100.39%
Formula
Percentage change = [(513 - 256) / 256] x 100
Subtract the new number by the original number
513 - 256 = 257
257 ÷ 256 = 1.00390625
1.00390625 x 100 = 100.39%