-4.08% is the change from 490 to 470
Calculation steps:
[( 470 - 490 ) ÷ 490] x 100 = -4.08%
Formula
Percentage change = [(470 - 490) / 490] x 100
Subtract the new number by the original number
470 - 490 = -20
-20 ÷ 490 = -0.04081632653061224
-0.04081632653061224 x 100 = -4.08%