-19.13% is the change from 800 to 647
Calculation steps:
[( 647 - 800 ) ÷ 800] x 100 = -19.13%
Formula
Percentage change = [(647 - 800) / 800] x 100
Subtract the new number by the original number
647 - 800 = -153
-153 ÷ 800 = -0.19125
-0.19125 x 100 = -19.13%