How do Mixed Classes actually work?

[charliethelongstalkedcat]

There is 2 years and so 2 topics...say history...year 2 is meant to be doing romans and year 1 is meant to be doing vikings....what do the other half of the class do while the other lot are being explained to about romans/vikings?
And literacy....year 2 have been through spellings and speech marks and full stops and capitals but year 1 havent...???

In my childens school subjects like history and science were covered on a 2 year rota. So even if the class is a mixture of year 5 & 6 all the children do the same work at the same time.It doesn't really matter if they 'do the Tudors' in year 5 or 6.