Canada: Win a sweepstakes, Do some Math?

I caught this post over at BoingBoing regarding special rules for Canadian winners of a Starbucks sweepstakes. Essentially if you win and you’re Canadian then you also have to solve some sort of math problem. For a few minutes I went through all the screwy reasons I could think of that this might be the case and then it suddenly occurred to me that Starbucks has no plainly visible business reason for implementing this clause. Canadians aren’t any worse at math than anyone else, generally speaking, so this doesn’t look like some kind of loophole that would allow Starbucks to decline payment of the prize. That being the case I quickly came to the conclusion that something this asinine must have origins in the law. Viola, Wikipedia knows all:

“Notably, Canada and several European countries require entrants to solve a mathematical puzzle, making it a contest of skill, in order to overcome requirements that would classify sweepstakes as a form of gambling.”

In this case specifically, avoiding breaking the law seems to be the idea. Now, I entertain myself with what kind of mathematical operation might be required of the winner. 1 + 1 if they’re blatantly side-stepping the law or possibly one of these if they’re more interested in holding onto their prize. Correct if I’m wrong but I believe that in the U.S. the prize must be placed in escrow (the company offering the prize cannot keep it even if no winner is forthcoming) for the sweepstakes to be legal.