32.5% is the change from 320 to 424
Calculation steps:
[( 424 - 320 ) ÷ 320] x 100 = 32.5%
Formula
Percentage change = [(424 - 320) / 320] x 100
Subtract the new number by the original number
424 - 320 = 104
104 ÷ 320 = 0.325
0.325 x 100 = 32.5%
Example