-18.37% is the change from 490 to 400
Calculation steps:
[( 400 - 490 ) ÷ 490] x 100 = -18.37%
Formula
Percentage change = [(400 - 490) / 490] x 100
Subtract the new number by the original number
400 - 490 = -90
-90 ÷ 490 = -0.1836734693877551
-0.1836734693877551 x 100 = -18.37%