40.66% is the change from 455 to 640
Calculation steps:
[( 640 - 455 ) ÷ 455] x 100 = 40.66%
Formula
Percentage change = [(640 - 455) / 455] x 100
Subtract the new number by the original number
640 - 455 = 185
185 ÷ 455 = 0.4065934065934066
0.4065934065934066 x 100 = 40.66%