-50.12% is the change from 840 to 419
Calculation steps:
[( 419 - 840 ) ÷ 840] x 100 = -50.12%
Formula
Percentage change = [(419 - 840) / 840] x 100
Subtract the new number by the original number
419 - 840 = -421
-421 ÷ 840 = -0.5011904761904762
-0.5011904761904762 x 100 = -50.12%
Example