-20% is the change from 270 to 216
Calculation steps:
[( 216 - 270 ) ÷ 270] x 100 = -20%
Formula
Percentage change = [(216 - 270) / 270] x 100
Subtract the new number by the original number
216 - 270 = -54
-54 ÷ 270 = -0.2
-0.2 x 100 = -20%
Example