-32.34% is the change from 640 to 433
Calculation steps:
[( 433 - 640 ) ÷ 640] x 100 = -32.34%
Formula
Percentage change = [(433 - 640) / 640] x 100
Subtract the new number by the original number
433 - 640 = -207
-207 ÷ 640 = -0.3234375
-0.3234375 x 100 = -32.34%