82% is the change from 50 to 91
Calculation steps:
[( 91 - 50 ) ÷ 50] x 100 = 82%
Formula
Percentage change = [(91 - 50) / 50] x 100
Subtract the new number by the original number
91 - 50 = 41
41 ÷ 50 = 0.82
0.82 x 100 = 82%
Example