-99% is the change from 600 to 6
Calculation steps:
[( 6 - 600 ) ÷ 600] x 100 = -99%
Formula
Percentage change = [(6 - 600) / 600] x 100
Subtract the new number by the original number
6 - 600 = -594
-594 ÷ 600 = -0.99
-0.99 x 100 = -99%
Example