It seems like you found a very interesting logic-math based game. In Twelve maybe math skills are not the most required qualities that you have to possess. You will need more luck than math knowledge because the rules to play the game are very simple. Just to click on two same numbers one after another and thus merge them. As you merge numbers they will split into two of which one of them is 1 and the other is for one number higher than the numbers you merged. This goal is to get the number Twelve and there you go- you will complete Twelve.