-80% is the change from 1000 to 200
Calculation steps:
[( 200 - 1000 ) ÷ 1000] x 100 = -80%
Formula
Percentage change = [(200 - 1000) / 1000] x 100
Subtract the new number by the original number
200 - 1000 = -800
-800 ÷ 1000 = -0.8
-0.8 x 100 = -80%
Example