One of the projects we completed during the long winter months cooped up in the house, was a racetrack around the basement. We measured an oval around the perimeter of the basement, drew the outline with a pencil, then, painted it in with black concrete paint. The pictures below show the finished product. We unveiled the racetrack to the kids on Christmas morning. We kept them out of the basement for a week while we did the measuring and painting. When they finally saw it, they were so shocked and excited. They also got new motorized cars to drive around, so it was a double whammy on Christmas morning.
The only things we needed to buy were paint rollers on poles and the paint. This was a fairly inexpensive project and the kids absolutely love it.