32.81% is the change from 256 to 340
Calculation steps:
[( 340 - 256 ) ÷ 256] x 100 = 32.81%
Formula
Percentage change = [(340 - 256) / 256] x 100
Subtract the new number by the original number
340 - 256 = 84
84 ÷ 256 = 0.328125
0.328125 x 100 = 32.81%