Wall mounted ball run. This would be great for kids who are too young for the marble runs. Could be used as a music installation if there are movable obstructions in the pipe that make sound when a ball touches them
Matematik med toalettrullar (Min blogg om allt mellan himmel och jord)
Tower of numbers: Each roll of toilet paper has a number on it. These toilet paper rolls will need to be placed in the correct order to create a tower. (Place a circle piece of paper between the rolls to make it easier to balance.