-80.84% is the change from 642 to 123
Calculation steps:
[( 123 - 642 ) ÷ 642] x 100 = -80.84%
Formula
Percentage change = [(123 - 642) / 642] x 100
Subtract the new number by the original number
123 - 642 = -519
-519 ÷ 642 = -0.8084112149532711
-0.8084112149532711 x 100 = -80.84%