-21% is the change from 900 to 711
Calculation steps:
[( 711 - 900 ) ÷ 900] x 100 = -21%
Formula
Percentage change = [(711 - 900) / 900] x 100
Subtract the new number by the original number
711 - 900 = -189
-189 ÷ 900 = -0.21
-0.21 x 100 = -21%
Example