We only have about 50 minutes of class, so we go bell to bell, there is no time for getting started on homework, or free time, unless I plan it in. This is why I love Whole Brain Teaching, it allows me to maximize my time so that we can do things like play games.
When my students bank time for free time, it is a very structured system. My students are in an ongoing competition, based on doing extra math. There are many different problems/puzzles they can work and they change on a regular basis. Some puzzles can only be completed once, some as much as they want. Each puzzle has a point value associated with it, and oce a week I update the scores on our score board. There is no end prize, they play to beat each other, to have bragging rights in the end.
I have tons of puzzles, and bonus problems, during this time they work to figure them out, many of the problems are first come first serve on points. If 2 people work together to figure a problem out, they split the points. Many of the puzzles and problems are from AIMS, state assesment problems (with answer choices removed), or puzzles I have made. We keep a scoring binder, I have 110 kids, so it can be a job, but it is worth it!
I am trying to attach some puzzles - if it doesn't work let me know... I will email them out.
Also, its rigged... sort of - I use it as a motivator for my low level students. We have homeroom and tutoring during the day. When I bringing low level students to do tutoring, I have a special folder marked 50 point problems, (which I never actually put out) after we have done some tutoring, I pump them up and get them to try a "tough" problem. The problem/puzzle is meant to challenge them at their level, and boosts their score - this is usually enough to get them on the scoreboard. My low level students always walk around with their heads held a little higher the next day - and it encourages my other students to earn more points.