-40% is the change from 35 to 21
Calculation steps:
[( 21 - 35 ) ÷ 35] x 100 = -40%
Formula
Percentage change = [(21 - 35) / 35] x 100
Subtract the new number by the original number
21 - 35 = -14
-14 ÷ 35 = -0.4
-0.4 x 100 = -40%
Example