-40.24% is the change from 840 to 502
Calculation steps:
[( 502 - 840 ) ÷ 840] x 100 = -40.24%
Formula
Percentage change = [(502 - 840) / 840] x 100
Subtract the new number by the original number
502 - 840 = -338
-338 ÷ 840 = -0.4023809523809524
-0.4023809523809524 x 100 = -40.24%