-35.71% is the change from 420 to 270
Calculation steps:
[( 270 - 420 ) ÷ 420] x 100 = -35.71%
Formula
Percentage change = [(270 - 420) / 420] x 100
Subtract the new number by the original number
270 - 420 = -150
-150 ÷ 420 = -0.35714285714285715
-0.35714285714285715 x 100 = -35.71%