26.88% is the change from 640 to 812
Calculation steps:
[( 812 - 640 ) ÷ 640] x 100 = 26.88%
Formula
Percentage change = [(812 - 640) / 640] x 100
Subtract the new number by the original number
812 - 640 = 172
172 ÷ 640 = 0.26875
0.26875 x 100 = 26.88%