-66% is the change from 900 to 306
Calculation steps:
[( 306 - 900 ) ÷ 900] x 100 = -66%
Formula
Percentage change = [(306 - 900) / 900] x 100
Subtract the new number by the original number
306 - 900 = -594
-594 ÷ 900 = -0.66
-0.66 x 100 = -66%
Example