-25% is the change from 180 to 135
Calculation steps:
[( 135 - 180 ) ÷ 180] x 100 = -25%
Formula
Percentage change = [(135 - 180) / 180] x 100
Subtract the new number by the original number
135 - 180 = -45
-45 ÷ 180 = -0.25
-0.25 x 100 = -25%
Example