-80.5% is the change from 646 to 126
Calculation steps:
[( 126 - 646 ) ÷ 646] x 100 = -80.5%
Formula
Percentage change = [(126 - 646) / 646] x 100
Subtract the new number by the original number
126 - 646 = -520
-520 ÷ 646 = -0.804953560371517
-0.804953560371517 x 100 = -80.5%