I play this game with my kids all the time and they LOVE IT! It's called "swipe the prize" and here's how it works:
Have the kids partner up and have every kid get a whiteboard, eraser and a marker.
You'll need index cards with the students' names on them (one name per card).
Draw a card and have that student pick a category (the points simply imply difficulty level, they don't accumulate)
ALL the students complete the problem on their whiteboards. They are supposed to compare answers with their partner. Draw a card and if that student has the right answer, he or she can choose a prize for him AND his partner. For example, I use an extra credit pass as a prize, so both kids would get an extra credit pass. That student then also gets to select the next category, and so on. Let's say that the next kid whose name is drawn has the right answer. That student can choose a different prize or swipe the other student's bonus pass prize. The game continues until the end of class. Whoever has the prizes at the end wins those prizes of course.
Prizes: I fill out three posted notes with the name of the prizes (homework pass, bonus pass and a piece of candy). The notes get passed around during class and at the end of class, the winners and their partners exchange the sticky notes for prizes.
Every kid gets reentered into every round, so it is possible for one group to walk out with all three prizes.
Just for kicks: These are random non-math questions that the kids have so much fun with. I call these "speed rounds." The student who writes the correct answer and holds their board up first wins that round. The kids get really into this and get loud and excited, so I don't "open" this category until four minutes remain in class.
Obviously, you can make your own adaptations to the game as you see fit :)