50% is the change from 60 to 90
Calculation steps:
[( 90 - 60 ) ÷ 60] x 100 = 50%
Formula
Percentage change = [(90 - 60) / 60] x 100
Subtract the new number by the original number
90 - 60 = 30
30 ÷ 60 = 0.5
0.5 x 100 = 50%
Example