100% is the change from 135 to 270
Calculation steps:
[( 270 - 135 ) ÷ 135] x 100 = 100%
Formula
Percentage change = [(270 - 135) / 135] x 100
Subtract the new number by the original number
270 - 135 = 135
135 ÷ 135 = 1
1 x 100 = 100%
Example