-65.16% is the change from 640 to 223
Calculation steps:
[( 223 - 640 ) ÷ 640] x 100 = -65.16%
Formula
Percentage change = [(223 - 640) / 640] x 100
Subtract the new number by the original number
223 - 640 = -417
-417 ÷ 640 = -0.6515625
-0.6515625 x 100 = -65.16%