-30% is the change from 60 to 42
Calculation steps:
[( 42 - 60 ) ÷ 60] x 100 = -30%
Formula
Percentage change = [(42 - 60) / 60] x 100
Subtract the new number by the original number
42 - 60 = -18
-18 ÷ 60 = -0.3
-0.3 x 100 = -30%
Example