My son came home with a styrofoam model of the planets and the sun (not to scale). We did a back of the envelope calculation to think about sizes and distances at the same time because "dad, can we put it at scale in the garden?". The Sun should be 2m in diameter when compared to his earth. Distance earth to sun would be about 200m, Neptune at 6km.

Though I know this in principle, I was again quite surprised - as was he.

Garden scale model: Sun 5mm, Earth 0.05mm. Space is big, Earth is small.