Toilet paper solar system to make in your home just using string and toilet paper and card or similar for the planets.
See the chart below for the scale. Take a piece of string and tie the planets (not forgetting the Sun at the start) at the appropriate places. 1 sheet of paper = 1 AU or the distance from the Sun to the Earth. You will need to be very careful with the placing of Mercury and Venus… 40 sheets of paper is really the minimum you need as any fewer and you will not be able to fit them on that first sheet so easily.