100% is the change from 140 to 280
Calculation steps:
[( 280 - 140 ) ÷ 140] x 100 = 100%
Formula
Percentage change = [(280 - 140) / 140] x 100
Subtract the new number by the original number
280 - 140 = 140
140 ÷ 140 = 1
1 x 100 = 100%
Example