The name of the game is Petals Around the Rose, and that name is significant. Newcomers to the game can be told that much. They can also be told that every answer is zero or an even number. They can also be told the answer for every throw of the dice that are used in the game. And that's all the information they get.
-- http://www.borrett.id.au/computing/petals-bg.htm
Here are some examples, see if you can work it out...
The answer is: 2 The answer is: 8
The answer is: 14 The answer is: 0
The answer is: 6 The answer is: 2
I am glad I worked it out fairly quickly, I think I would have been very pissed with myself had I taken a long time! Unless you work it out right away, you'll be slapping yourself and thinking "DUH why didn't I think that!".
Bill Gates took ages: http://www.borrett.id.au/computing/petals-bg.htm
More examples via this flash game: http://www.freeworldgroup.com/games/roses/