-55% is the change from 300 to 135
Calculation steps:
[( 135 - 300 ) ÷ 300] x 100 = -55%
Formula
Percentage change = [(135 - 300) / 300] x 100
Subtract the new number by the original number
135 - 300 = -165
-165 ÷ 300 = -0.55
-0.55 x 100 = -55%
Example