-83.8% is the change from 642 to 104
Calculation steps:
[( 104 - 642 ) ÷ 642] x 100 = -83.8%
Formula
Percentage change = [(104 - 642) / 642] x 100
Subtract the new number by the original number
104 - 642 = -538
-538 ÷ 642 = -0.838006230529595
-0.838006230529595 x 100 = -83.8%