900% is the change from 28 to 280
Calculation steps:
[( 280 - 28 ) ÷ 28] x 100 = 900%
Formula
Percentage change = [(280 - 28) / 28] x 100
Subtract the new number by the original number
280 - 28 = 252
252 ÷ 28 = 9
9 x 100 = 900%
Example