-21.24% is the change from 838 to 660
Calculation steps:
[( 660 - 838 ) ÷ 838] x 100 = -21.24%
Formula
Percentage change = [(660 - 838) / 838] x 100
Subtract the new number by the original number
660 - 838 = -178
-178 ÷ 838 = -0.21241050119331742
-0.21241050119331742 x 100 = -21.24%