-46.88% is the change from 64 to 34
Calculation steps:
[( 34 - 64 ) ÷ 64] x 100 = -46.88%
Formula
Percentage change = [(34 - 64) / 64] x 100
Subtract the new number by the original number
34 - 64 = -30
-30 ÷ 64 = -0.46875
-0.46875 x 100 = -46.88%
Example