-50.29% is the change from 680 to 338
Calculation steps:
[( 338 - 680 ) ÷ 680] x 100 = -50.29%
Formula
Percentage change = [(338 - 680) / 680] x 100
Subtract the new number by the original number
338 - 680 = -342
-342 ÷ 680 = -0.5029411764705882
-0.5029411764705882 x 100 = -50.29%