70% is the change from 150 to 255
Calculation steps:
[( 255 - 150 ) ÷ 150] x 100 = 70%
Formula
Percentage change = [(255 - 150) / 150] x 100
Subtract the new number by the original number
255 - 150 = 105
105 ÷ 150 = 0.7
0.7 x 100 = 70%
Example