-38.75% is the change from 80 to 49
Calculation steps:
[( 49 - 80 ) ÷ 80] x 100 = -38.75%
Formula
Percentage change = [(49 - 80) / 80] x 100
Subtract the new number by the original number
49 - 80 = -31
-31 ÷ 80 = -0.3875
-0.3875 x 100 = -38.75%
Example