-20% is the change from 210 to 168
Calculation steps:
[( 168 - 210 ) ÷ 210] x 100 = -20%
Formula
Percentage change = [(168 - 210) / 210] x 100
Subtract the new number by the original number
168 - 210 = -42
-42 ÷ 210 = -0.2
-0.2 x 100 = -20%
Example