-80.69% is the change from 642 to 124
Calculation steps:
[( 124 - 642 ) ÷ 642] x 100 = -80.69%
Formula
Percentage change = [(124 - 642) / 642] x 100
Subtract the new number by the original number
124 - 642 = -518
-518 ÷ 642 = -0.8068535825545171
-0.8068535825545171 x 100 = -80.69%