-25% is the change from 240 to 180
Calculation steps:
[( 180 - 240 ) ÷ 240] x 100 = -25%
Formula
Percentage change = [(180 - 240) / 240] x 100
Subtract the new number by the original number
180 - 240 = -60
-60 ÷ 240 = -0.25
-0.25 x 100 = -25%
Example