50% is the change from 450 to 675
Calculation steps:
[( 675 - 450 ) ÷ 450] x 100 = 50%
Formula
Percentage change = [(675 - 450) / 450] x 100
Subtract the new number by the original number
675 - 450 = 225
225 ÷ 450 = 0.5
0.5 x 100 = 50%
Example