3.13% is the change from 320 to 330
Calculation steps:
[( 330 - 320 ) ÷ 320] x 100 = 3.13%
Formula
Percentage change = [(330 - 320) / 320] x 100
Subtract the new number by the original number
330 - 320 = 10
10 ÷ 320 = 0.03125
0.03125 x 100 = 3.13%
Example