-98.45% is the change from 645 to 10
Calculation steps:
[( 10 - 645 ) ÷ 645] x 100 = -98.45%
Formula
Percentage change = [(10 - 645) / 645] x 100
Subtract the new number by the original number
10 - 645 = -635
-635 ÷ 645 = -0.9844961240310077
-0.9844961240310077 x 100 = -98.45%