-40.47% is the change from 640 to 381
Calculation steps:
[( 381 - 640 ) ÷ 640] x 100 = -40.47%
Formula
Percentage change = [(381 - 640) / 640] x 100
Subtract the new number by the original number
381 - 640 = -259
-259 ÷ 640 = -0.4046875
-0.4046875 x 100 = -40.47%