-40% is the change from 205 to 123
Calculation steps:
[( 123 - 205 ) ÷ 205] x 100 = -40%
Formula
Percentage change = [(123 - 205) / 205] x 100
Subtract the new number by the original number
123 - 205 = -82
-82 ÷ 205 = -0.4
-0.4 x 100 = -40%
Example