400% is the change from 80 to 400
Calculation steps:
[( 400 - 80 ) ÷ 80] x 100 = 400%
Formula
Percentage change = [(400 - 80) / 80] x 100
Subtract the new number by the original number
400 - 80 = 320
320 ÷ 80 = 4
4 x 100 = 400%
Example