151.56% is the change from 256 to 644
Calculation steps:
[( 644 - 256 ) ÷ 256] x 100 = 151.56%
Formula
Percentage change = [(644 - 256) / 256] x 100
Subtract the new number by the original number
644 - 256 = 388
388 ÷ 256 = 1.515625
1.515625 x 100 = 151.56%