-98.8% is the change from 250 to 3
Calculation steps:
[( 3 - 250 ) ÷ 250] x 100 = -98.8%
Formula
Percentage change = [(3 - 250) / 250] x 100
Subtract the new number by the original number
3 - 250 = -247
-247 ÷ 250 = -0.988
-0.988 x 100 = -98.8%
Example