-40% is the change from 200 to 120
Calculation steps:
[( 120 - 200 ) ÷ 200] x 100 = -40%
Formula
Percentage change = [(120 - 200) / 200] x 100
Subtract the new number by the original number
120 - 200 = -80
-80 ÷ 200 = -0.4
-0.4 x 100 = -40%
Example