-50% is the change from 878 to 439
Calculation steps:
[( 439 - 878 ) ÷ 878] x 100 = -50%
Formula
Percentage change = [(439 - 878) / 878] x 100
Subtract the new number by the original number
439 - 878 = -439
-439 ÷ 878 = -0.5
-0.5 x 100 = -50%
Example