-34.98% is the change from 646 to 420
Calculation steps:
[( 420 - 646 ) ÷ 646] x 100 = -34.98%
Formula
Percentage change = [(420 - 646) / 646] x 100
Subtract the new number by the original number
420 - 646 = -226
-226 ÷ 646 = -0.3498452012383901
-0.3498452012383901 x 100 = -34.98%