-7.14% is the change from 280 to 260
Calculation steps:
[( 260 - 280 ) ÷ 280] x 100 = -7.14%
Formula
Percentage change = [(260 - 280) / 280] x 100
Subtract the new number by the original number
260 - 280 = -20
-20 ÷ 280 = -0.07142857142857142
-0.07142857142857142 x 100 = -7.14%