70% is the change from 80 to 136
Calculation steps:
[( 136 - 80 ) ÷ 80] x 100 = 70%
Formula
Percentage change = [(136 - 80) / 80] x 100
Subtract the new number by the original number
136 - 80 = 56
56 ÷ 80 = 0.7
0.7 x 100 = 70%
Example