-70% is the change from 900 to 270
Calculation steps:
[( 270 - 900 ) ÷ 900] x 100 = -70%
Formula
Percentage change = [(270 - 900) / 900] x 100
Subtract the new number by the original number
270 - 900 = -630
-630 ÷ 900 = -0.7
-0.7 x 100 = -70%
Example