53.13% is the change from 640 to 980
Calculation steps:
[( 980 - 640 ) ÷ 640] x 100 = 53.13%
Formula
Percentage change = [(980 - 640) / 640] x 100
Subtract the new number by the original number
980 - 640 = 340
340 ÷ 640 = 0.53125
0.53125 x 100 = 53.13%