9% is the change from 500 to 545
Calculation steps:
[( 545 - 500 ) ÷ 500] x 100 = 9%
Formula
Percentage change = [(545 - 500) / 500] x 100
Subtract the new number by the original number
545 - 500 = 45
45 ÷ 500 = 0.09
0.09 x 100 = 9%
Example