-23.27% is the change from 838 to 643
Calculation steps:
[( 643 - 838 ) ÷ 838] x 100 = -23.27%
Formula
Percentage change = [(643 - 838) / 838] x 100
Subtract the new number by the original number
643 - 838 = -195
-195 ÷ 838 = -0.23269689737470167
-0.23269689737470167 x 100 = -23.27%