6400% is the change from 6 to 390
Calculation steps:
[( 390 - 6 ) ÷ 6] x 100 = 6400%
Formula
Percentage change = [(390 - 6) / 6] x 100
Subtract the new number by the original number
390 - 6 = 384
384 ÷ 6 = 64
64 x 100 = 6400%
Example