Marble Races with a cheap pool noodle (occupies the kids for hours.) Did this, but instead of cutting the pool noodle, the marble is small enough to fit inside the full noodle to roll down. Then can use the noodle for other things too!
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.