-42.58% is the change from 512 to 294
Calculation steps:
[( 294 - 512 ) ÷ 512] x 100 = -42.58%
Formula
Percentage change = [(294 - 512) / 512] x 100
Subtract the new number by the original number
294 - 512 = -218
-218 ÷ 512 = -0.42578125
-0.42578125 x 100 = -42.58%