-84% is the change from 50 to 8
Calculation steps:
[( 8 - 50 ) ÷ 50] x 100 = -84%
Formula
Percentage change = [(8 - 50) / 50] x 100
Subtract the new number by the original number
8 - 50 = -42
-42 ÷ 50 = -0.84
-0.84 x 100 = -84%
Example