-51% is the change from 1000 to 490
Calculation steps:
[( 490 - 1000 ) ÷ 1000] x 100 = -51%
Formula
Percentage change = [(490 - 1000) / 1000] x 100
Subtract the new number by the original number
490 - 1000 = -510
-510 ÷ 1000 = -0.51
-0.51 x 100 = -51%