-89.74% is the change from 780 to 80
Calculation steps:
[( 80 - 780 ) ÷ 780] x 100 = -89.74%
Formula
Percentage change = [(80 - 780) / 780] x 100
Subtract the new number by the original number
80 - 780 = -700
-700 ÷ 780 = -0.8974358974358975
-0.8974358974358975 x 100 = -89.74%