52.81% is the change from 640 to 978
Calculation steps:
[( 978 - 640 ) ÷ 640] x 100 = 52.81%
Formula
Percentage change = [(978 - 640) / 640] x 100
Subtract the new number by the original number
978 - 640 = 338
338 ÷ 640 = 0.528125
0.528125 x 100 = 52.81%