-98% is the change from 400 to 8
Calculation steps:
[( 8 - 400 ) ÷ 400] x 100 = -98%
Formula
Percentage change = [(8 - 400) / 400] x 100
Subtract the new number by the original number
8 - 400 = -392
-392 ÷ 400 = -0.98
-0.98 x 100 = -98%
Example