-89.66% is the change from 290 to 30
Calculation steps:
[( 30 - 290 ) ÷ 290] x 100 = -89.66%
Formula
Percentage change = [(30 - 290) / 290] x 100
Subtract the new number by the original number
30 - 290 = -260
-260 ÷ 290 = -0.896551724137931
-0.896551724137931 x 100 = -89.66%