300% is the change from 20 to 80
Calculation steps:
[( 80 - 20 ) ÷ 20] x 100 = 300%
Formula
Percentage change = [(80 - 20) / 20] x 100
Subtract the new number by the original number
80 - 20 = 60
60 ÷ 20 = 3
3 x 100 = 300%
Example