-59.53% is the change from 640 to 259
Calculation steps:
[( 259 - 640 ) ÷ 640] x 100 = -59.53%
Formula
Percentage change = [(259 - 640) / 640] x 100
Subtract the new number by the original number
259 - 640 = -381
-381 ÷ 640 = -0.5953125
-0.5953125 x 100 = -59.53%