-29.38% is the change from 640 to 452
Calculation steps:
[( 452 - 640 ) ÷ 640] x 100 = -29.38%
Formula
Percentage change = [(452 - 640) / 640] x 100
Subtract the new number by the original number
452 - 640 = -188
-188 ÷ 640 = -0.29375
-0.29375 x 100 = -29.38%