40% is the change from 320 to 448
Calculation steps:
[( 448 - 320 ) ÷ 320] x 100 = 40%
Formula
Percentage change = [(448 - 320) / 320] x 100
Subtract the new number by the original number
448 - 320 = 128
128 ÷ 320 = 0.4
0.4 x 100 = 40%
Example