Domains, scales and units are confusing

[LourensVeen]

During our first trial teaching event, there was quite a bit of confusion about domains, scales and units. In the lesson, we have people come up with their own coupled simulation. That's good, but it would be good if we had a running example as well, and then explicitly discuss the domain (where/when), the scale (how big/how fast) and the units (reference size we happen to use).