-88.44% is the change from 640 to 74
Calculation steps:
[( 74 - 640 ) ÷ 640] x 100 = -88.44%
Formula
Percentage change = [(74 - 640) / 640] x 100
Subtract the new number by the original number
74 - 640 = -566
-566 ÷ 640 = -0.884375
-0.884375 x 100 = -88.44%
Example