3.23% is the change from 310 to 320
Calculation steps:
[( 320 - 310 ) ÷ 310] x 100 = 3.23%
Formula
Percentage change = [(320 - 310) / 310] x 100
Subtract the new number by the original number
320 - 310 = 10
10 ÷ 310 = 0.03225806451612903
0.03225806451612903 x 100 = 3.23%