80% is the change from 400 to 720
Calculation steps:
[( 720 - 400 ) ÷ 400] x 100 = 80%
Formula
Percentage change = [(720 - 400) / 400] x 100
Subtract the new number by the original number
720 - 400 = 320
320 ÷ 400 = 0.8
0.8 x 100 = 80%
Example