50.39% is the change from 512 to 770
Calculation steps:
[( 770 - 512 ) ÷ 512] x 100 = 50.39%
Formula
Percentage change = [(770 - 512) / 512] x 100
Subtract the new number by the original number
770 - 512 = 258
258 ÷ 512 = 0.50390625
0.50390625 x 100 = 50.39%