50.94% is the change from 424 to 640
Calculation steps:
[( 640 - 424 ) ÷ 424] x 100 = 50.94%
Formula
Percentage change = [(640 - 424) / 424] x 100
Subtract the new number by the original number
640 - 424 = 216
216 ÷ 424 = 0.5094339622641509
0.5094339622641509 x 100 = 50.94%