-49.4% is the change from 840 to 425
Calculation steps:
[( 425 - 840 ) ÷ 840] x 100 = -49.4%
Formula
Percentage change = [(425 - 840) / 840] x 100
Subtract the new number by the original number
425 - 840 = -415
-415 ÷ 840 = -0.49404761904761907
-0.49404761904761907 x 100 = -49.4%