Do you have a concrete or paved surface? Do you have some chalk? Great - this will take you five minutes to set up!
Use your chalk to draw out a race track. We used the area at the top of our driveway. If your children are older they can design and draw their own track.
Get your children to choose their racers. We raced crabs and ladybugs today but toy cars are probably the obvious choice. Doesn't matter though - I suspect we'll be having My Little Pony races next.
If your kids are feeling creative they can decorate the racing track - we used duplo blocks to make a bridge. You can also use more chalk to draw various features like grandstands for spectators or water features.
Need to get rid of it? (or do your kids want to make amendments to their race track?) Just wash it away with water.
For more school holiday activity ideas, see all the posts here.