50% is the change from 34 to 51
Calculation steps:
[( 51 - 34 ) ÷ 34] x 100 = 50%
Formula
Percentage change = [(51 - 34) / 34] x 100
Subtract the new number by the original number
51 - 34 = 17
17 ÷ 34 = 0.5
0.5 x 100 = 50%
Example