150% is the change from 40 to 100
Calculation steps:
[( 100 - 40 ) ÷ 40] x 100 = 150%
Formula
Percentage change = [(100 - 40) / 40] x 100
Subtract the new number by the original number
100 - 40 = 60
60 ÷ 40 = 1.5
1.5 x 100 = 150%
Example