98.43% is the change from 255 to 506
Calculation steps:
[( 506 - 255 ) ÷ 255] x 100 = 98.43%
Formula
Percentage change = [(506 - 255) / 255] x 100
Subtract the new number by the original number
506 - 255 = 251
251 ÷ 255 = 0.984313725490196
0.984313725490196 x 100 = 98.43%