-77.78% is the change from 180 to 40
Calculation steps:
[( 40 - 180 ) ÷ 180] x 100 = -77.78%
Formula
Percentage change = [(40 - 180) / 180] x 100
Subtract the new number by the original number
40 - 180 = -140
-140 ÷ 180 = -0.7777777777777778
-0.7777777777777778 x 100 = -77.78%