-47.66% is the change from 642 to 336
Calculation steps:
[( 336 - 642 ) ÷ 642] x 100 = -47.66%
Formula
Percentage change = [(336 - 642) / 642] x 100
Subtract the new number by the original number
336 - 642 = -306
-306 ÷ 642 = -0.4766355140186916
-0.4766355140186916 x 100 = -47.66%