28.91% is the change from 640 to 825
Calculation steps:
[( 825 - 640 ) ÷ 640] x 100 = 28.91%
Formula
Percentage change = [(825 - 640) / 640] x 100
Subtract the new number by the original number
825 - 640 = 185
185 ÷ 640 = 0.2890625
0.2890625 x 100 = 28.91%