100% is the change from 336 to 672
Calculation steps:
[( 672 - 336 ) ÷ 336] x 100 = 100%
Formula
Percentage change = [(672 - 336) / 336] x 100
Subtract the new number by the original number
672 - 336 = 336
336 ÷ 336 = 1
1 x 100 = 100%
Example