15850% is the change from 4 to 638
Calculation steps:
[( 638 - 4 ) ÷ 4] x 100 = 15850%
Formula
Percentage change = [(638 - 4) / 4] x 100
Subtract the new number by the original number
638 - 4 = 634
634 ÷ 4 = 158.5
158.5 x 100 = 15850%
Example