-30% is the change from 180 to 126
Calculation steps:
[( 126 - 180 ) ÷ 180] x 100 = -30%
Formula
Percentage change = [(126 - 180) / 180] x 100
Subtract the new number by the original number
126 - 180 = -54
-54 ÷ 180 = -0.3
-0.3 x 100 = -30%
Example