-40% is the change from 45 to 27
Calculation steps:
[( 27 - 45 ) ÷ 45] x 100 = -40%
Formula
Percentage change = [(27 - 45) / 45] x 100
Subtract the new number by the original number
27 - 45 = -18
-18 ÷ 45 = -0.4
-0.4 x 100 = -40%
Example