100% is the change from 70 to 140
Calculation steps:
[( 140 - 70 ) ÷ 70] x 100 = 100%
Formula
Percentage change = [(140 - 70) / 70] x 100
Subtract the new number by the original number
140 - 70 = 70
70 ÷ 70 = 1
1 x 100 = 100%
Example