-3% is the change from 900 to 873
Calculation steps:
[( 873 - 900 ) ÷ 900] x 100 = -3%
Formula
Percentage change = [(873 - 900) / 900] x 100
Subtract the new number by the original number
873 - 900 = -27
-27 ÷ 900 = -0.03
-0.03 x 100 = -3%
Example