-53.13% is the change from 512 to 240
Calculation steps:
[( 240 - 512 ) ÷ 512] x 100 = -53.13%
Formula
Percentage change = [(240 - 512) / 512] x 100
Subtract the new number by the original number
240 - 512 = -272
-272 ÷ 512 = -0.53125
-0.53125 x 100 = -53.13%