286.72% is the change from 256 to 990
Calculation steps:
[( 990 - 256 ) ÷ 256] x 100 = 286.72%
Formula
Percentage change = [(990 - 256) / 256] x 100
Subtract the new number by the original number
990 - 256 = 734
734 ÷ 256 = 2.8671875
2.8671875 x 100 = 286.72%