-90% is the change from 490 to 49
Calculation steps:
[( 49 - 490 ) ÷ 490] x 100 = -90%
Formula
Percentage change = [(49 - 490) / 490] x 100
Subtract the new number by the original number
49 - 490 = -441
-441 ÷ 490 = -0.9
-0.9 x 100 = -90%
Example