800% is the change from 1 to 9
Calculation steps:
[( 9 - 1 ) ÷ 1] x 100 = 800%
Formula
Percentage change = [(9 - 1) / 1] x 100
Subtract the new number by the original number
9 - 1 = 8
8 ÷ 1 = 8
8 x 100 = 800%
Example