107.5% is the change from 320 to 664
Calculation steps:
[( 664 - 320 ) ÷ 320] x 100 = 107.5%
Formula
Percentage change = [(664 - 320) / 320] x 100
Subtract the new number by the original number
664 - 320 = 344
344 ÷ 320 = 1.075
1.075 x 100 = 107.5%
Example