-98.76% is the change from 646 to 8
Calculation steps:
[( 8 - 646 ) ÷ 646] x 100 = -98.76%
Formula
Percentage change = [(8 - 646) / 646] x 100
Subtract the new number by the original number
8 - 646 = -638
-638 ÷ 646 = -0.9876160990712074
-0.9876160990712074 x 100 = -98.76%