-74.69% is the change from 640 to 162
Calculation steps:
[( 162 - 640 ) ÷ 640] x 100 = -74.69%
Formula
Percentage change = [(162 - 640) / 640] x 100
Subtract the new number by the original number
162 - 640 = -478
-478 ÷ 640 = -0.746875
-0.746875 x 100 = -74.69%