-50% is the change from 108 to 54
Calculation steps:
[( 54 - 108 ) ÷ 108] x 100 = -50%
Formula
Percentage change = [(54 - 108) / 108] x 100
Subtract the new number by the original number
54 - 108 = -54
-54 ÷ 108 = -0.5
-0.5 x 100 = -50%
Example