100% is the change from 335 to 670
Calculation steps:
[( 670 - 335 ) ÷ 335] x 100 = 100%
Formula
Percentage change = [(670 - 335) / 335] x 100
Subtract the new number by the original number
670 - 335 = 335
335 ÷ 335 = 1
1 x 100 = 100%
Example