3890% is the change from 10 to 399
Calculation steps:
[( 399 - 10 ) ÷ 10] x 100 = 3890%
Formula
Percentage change = [(399 - 10) / 10] x 100
Subtract the new number by the original number
399 - 10 = 389
389 ÷ 10 = 38.9
38.9 x 100 = 3890%
Example