Hi Laura,
making those comparisons is fun. I sometimes ask second level students roughly how big they think the world is.
We start from – how long does it take a plane to get to Australia- which is half way around the world. They say – about a day or 24 hours. (ish)
Then I ask – how far does a plane go in an hour (ish). If they don’t know (and they usually don’t) we break it down to – if you took a plane from Cork to Dublin, how long would it take once you were in the air – and how far is Dublin – so that’s roughly the speed of an airplane.
It’s all very ish. Then we look at going to the Moon, since the Moon is 30 Earth diameters away (or 10 circumferences), so if it takes a day to get to Australia in a plane, it will take 20 days to get to the Moon (ish).
If you want to look at a bigger comparison table: