-65% is the change from 800 to 280
Calculation steps:
[( 280 - 800 ) ÷ 800] x 100 = -65%
Formula
Percentage change = [(280 - 800) / 800] x 100
Subtract the new number by the original number
280 - 800 = -520
-520 ÷ 800 = -0.65
-0.65 x 100 = -65%
Example