53.28% is the change from 640 to 981
Calculation steps:
[( 981 - 640 ) ÷ 640] x 100 = 53.28%
Formula
Percentage change = [(981 - 640) / 640] x 100
Subtract the new number by the original number
981 - 640 = 341
341 ÷ 640 = 0.5328125
0.5328125 x 100 = 53.28%