-50.5% is the change from 800 to 396
Calculation steps:
[( 396 - 800 ) ÷ 800] x 100 = -50.5%
Formula
Percentage change = [(396 - 800) / 800] x 100
Subtract the new number by the original number
396 - 800 = -404
-404 ÷ 800 = -0.505
-0.505 x 100 = -50.5%