-55.16% is the change from 640 to 287
Calculation steps:
[( 287 - 640 ) ÷ 640] x 100 = -55.16%
Formula
Percentage change = [(287 - 640) / 640] x 100
Subtract the new number by the original number
287 - 640 = -353
-353 ÷ 640 = -0.5515625
-0.5515625 x 100 = -55.16%