275% is the change from 240 to 900
Calculation steps:
[( 900 - 240 ) ÷ 240] x 100 = 275%
Formula
Percentage change = [(900 - 240) / 240] x 100
Subtract the new number by the original number
900 - 240 = 660
660 ÷ 240 = 2.75
2.75 x 100 = 275%
Example