-2% is the change from 50 to 49
Calculation steps:
[( 49 - 50 ) ÷ 50] x 100 = -2%
Formula
Percentage change = [(49 - 50) / 50] x 100
Subtract the new number by the original number
49 - 50 = -1
-1 ÷ 50 = -0.02
-0.02 x 100 = -2%
Example