13.75% is the change from 640 to 728
Calculation steps:
[( 728 - 640 ) ÷ 640] x 100 = 13.75%
Formula
Percentage change = [(728 - 640) / 640] x 100
Subtract the new number by the original number
728 - 640 = 88
88 ÷ 640 = 0.1375
0.1375 x 100 = 13.75%
Example