-87.5% is the change from 40 to 5
Calculation steps:
[( 5 - 40 ) ÷ 40] x 100 = -87.5%
Formula
Percentage change = [(5 - 40) / 40] x 100
Subtract the new number by the original number
5 - 40 = -35
-35 ÷ 40 = -0.875
-0.875 x 100 = -87.5%
Example