20.16% is the change from 640 to 769
Calculation steps:
[( 769 - 640 ) ÷ 640] x 100 = 20.16%
Formula
Percentage change = [(769 - 640) / 640] x 100
Subtract the new number by the original number
769 - 640 = 129
129 ÷ 640 = 0.2015625
0.2015625 x 100 = 20.16%