-24.26% is the change from 845 to 640
Calculation steps:
[( 640 - 845 ) ÷ 845] x 100 = -24.26%
Formula
Percentage change = [(640 - 845) / 845] x 100
Subtract the new number by the original number
640 - 845 = -205
-205 ÷ 845 = -0.24260355029585798
-0.24260355029585798 x 100 = -24.26%