-81.88% is the change from 640 to 116
Calculation steps:
[( 116 - 640 ) ÷ 640] x 100 = -81.88%
Formula
Percentage change = [(116 - 640) / 640] x 100
Subtract the new number by the original number
116 - 640 = -524
-524 ÷ 640 = -0.81875
-0.81875 x 100 = -81.88%