-87.83% is the change from 649 to 79
Calculation steps:
[( 79 - 649 ) ÷ 649] x 100 = -87.83%
Formula
Percentage change = [(79 - 649) / 649] x 100
Subtract the new number by the original number
79 - 649 = -570
-570 ÷ 649 = -0.8782742681047766
-0.8782742681047766 x 100 = -87.83%