-50% is the change from 54 to 27
Calculation steps:
[( 27 - 54 ) ÷ 54] x 100 = -50%
Formula
Percentage change = [(27 - 54) / 54] x 100
Subtract the new number by the original number
27 - 54 = -27
-27 ÷ 54 = -0.5
-0.5 x 100 = -50%
Example