-27.19% is the change from 640 to 466
Calculation steps:
[( 466 - 640 ) ÷ 640] x 100 = -27.19%
Formula
Percentage change = [(466 - 640) / 640] x 100
Subtract the new number by the original number
466 - 640 = -174
-174 ÷ 640 = -0.271875
-0.271875 x 100 = -27.19%