45% is the change from 420 to 609
Calculation steps:
[( 609 - 420 ) ÷ 420] x 100 = 45%
Formula
Percentage change = [(609 - 420) / 420] x 100
Subtract the new number by the original number
609 - 420 = 189
189 ÷ 420 = 0.45
0.45 x 100 = 45%
Example