20% is the change from 270 to 324
Calculation steps:
[( 324 - 270 ) ÷ 270] x 100 = 20%
Formula
Percentage change = [(324 - 270) / 270] x 100
Subtract the new number by the original number
324 - 270 = 54
54 ÷ 270 = 0.2
0.2 x 100 = 20%
Example