-85% is the change from 80 to 12
Calculation steps:
[( 12 - 80 ) ÷ 80] x 100 = -85%
Formula
Percentage change = [(12 - 80) / 80] x 100
Subtract the new number by the original number
12 - 80 = -68
-68 ÷ 80 = -0.85
-0.85 x 100 = -85%
Example