400% is the change from 21 to 105
Calculation steps:
[( 105 - 21 ) ÷ 21] x 100 = 400%
Formula
Percentage change = [(105 - 21) / 21] x 100
Subtract the new number by the original number
105 - 21 = 84
84 ÷ 21 = 4
4 x 100 = 400%
Example