35.31% is the change from 640 to 866
Calculation steps:
[( 866 - 640 ) ÷ 640] x 100 = 35.31%
Formula
Percentage change = [(866 - 640) / 640] x 100
Subtract the new number by the original number
866 - 640 = 226
226 ÷ 640 = 0.353125
0.353125 x 100 = 35.31%