-35.8% is the change from 1000 to 642
Calculation steps:
[( 642 - 1000 ) ÷ 1000] x 100 = -35.8%
Formula
Percentage change = [(642 - 1000) / 1000] x 100
Subtract the new number by the original number
642 - 1000 = -358
-358 ÷ 1000 = -0.358
-0.358 x 100 = -35.8%