-62.5% is the change from 64 to 24
Calculation steps:
[( 24 - 64 ) ÷ 64] x 100 = -62.5%
Formula
Percentage change = [(24 - 64) / 64] x 100
Subtract the new number by the original number
24 - 64 = -40
-40 ÷ 64 = -0.625
-0.625 x 100 = -62.5%
Example