-52.94% is the change from 680 to 320
Calculation steps:
[( 320 - 680 ) ÷ 680] x 100 = -52.94%
Formula
Percentage change = [(320 - 680) / 680] x 100
Subtract the new number by the original number
320 - 680 = -360
-360 ÷ 680 = -0.5294117647058824
-0.5294117647058824 x 100 = -52.94%