-35.71% is the change from 840 to 540
Calculation steps:
[( 540 - 840 ) ÷ 840] x 100 = -35.71%
Formula
Percentage change = [(540 - 840) / 840] x 100
Subtract the new number by the original number
540 - 840 = -300
-300 ÷ 840 = -0.35714285714285715
-0.35714285714285715 x 100 = -35.71%