-80% is the change from 635 to 127
Calculation steps:
[( 127 - 635 ) ÷ 635] x 100 = -80%
Formula
Percentage change = [(127 - 635) / 635] x 100
Subtract the new number by the original number
127 - 635 = -508
-508 ÷ 635 = -0.8
-0.8 x 100 = -80%
Example