81.48% is the change from 270 to 490
Calculation steps:
[( 490 - 270 ) ÷ 270] x 100 = 81.48%
Formula
Percentage change = [(490 - 270) / 270] x 100
Subtract the new number by the original number
490 - 270 = 220
220 ÷ 270 = 0.8148148148148148
0.8148148148148148 x 100 = 81.48%