200% is the change from 102 to 306
Calculation steps:
[( 306 - 102 ) ÷ 102] x 100 = 200%
Formula
Percentage change = [(306 - 102) / 102] x 100
Subtract the new number by the original number
306 - 102 = 204
204 ÷ 102 = 2
2 x 100 = 200%
Example