Facts always need refreshing. Play this game with division and multiplication. Kids work in groups of 3s. Give scoring paper if you want to do the second part of what I propose. Each group needs a pack of cards. (You can make them too, for part of the class if you need to with construction paper and markers and scissors.........easy). Anyway, two kids take a card without looking and hold them up on their foreheads. The third gives a product or quotient involving the two cards. The first one to say their own card by looking at the other kid's card and figuring it out based on the number given, gets a point/buck (or 5 or 10.........whatever).
Now, you can also take the last half of class for a silent auction. Auction off just little stuff, school supplies, whatever..................make a paper for each thing, and put a total on the top. The kids have to write down their bid in percents of the total. For example, a pack of markers is worth 50 points/bucks. Kid A bids 10% or 5 points/bucks. Kid B bids 25% or 12.50. And so on. You can have two columns for them to bid the percent and then write how much it would be in points/bucks. If you have an old Monopoly game you can use that money..........they love that.
Edited to say points and bucks in there, because I kept saying one or the other and thought it was confusing. We often call them "bear bucks" if our mascots are the bears..............
Anyway, you'd have to have the prizes, but that's it. You can make the cards in the first 5 minutes of class, no problem.
That's all I've got right now, maybe I'll come up with more later.