-3.45% is the change from 290 to 280
Calculation steps:
[( 280 - 290 ) ÷ 290] x 100 = -3.45%
Formula
Percentage change = [(280 - 290) / 290] x 100
Subtract the new number by the original number
280 - 290 = -10
-10 ÷ 290 = -0.034482758620689655
-0.034482758620689655 x 100 = -3.45%