-83.1% is the change from 840 to 142
Calculation steps:
[( 142 - 840 ) ÷ 840] x 100 = -83.1%
Formula
Percentage change = [(142 - 840) / 840] x 100
Subtract the new number by the original number
142 - 840 = -698
-698 ÷ 840 = -0.830952380952381
-0.830952380952381 x 100 = -83.1%