20% is the change from 90 to 108
Calculation steps:
[( 108 - 90 ) ÷ 90] x 100 = 20%
Formula
Percentage change = [(108 - 90) / 90] x 100
Subtract the new number by the original number
108 - 90 = 18
18 ÷ 90 = 0.2
0.2 x 100 = 20%
Example