-16% is the change from 50 to 42
Calculation steps:
[( 42 - 50 ) ÷ 50] x 100 = -16%
Formula
Percentage change = [(42 - 50) / 50] x 100
Subtract the new number by the original number
42 - 50 = -8
-8 ÷ 50 = -0.16
-0.16 x 100 = -16%
Example