-40% is the change from 680 to 408
Calculation steps:
[( 408 - 680 ) ÷ 680] x 100 = -40%
Formula
Percentage change = [(408 - 680) / 680] x 100
Subtract the new number by the original number
408 - 680 = -272
-272 ÷ 680 = -0.4
-0.4 x 100 = -40%
Example