-50.98% is the change from 512 to 251
Calculation steps:
[( 251 - 512 ) ÷ 512] x 100 = -50.98%
Formula
Percentage change = [(251 - 512) / 512] x 100
Subtract the new number by the original number
251 - 512 = -261
-261 ÷ 512 = -0.509765625
-0.509765625 x 100 = -50.98%