Hi. I am teaching problem soving in maths to a mixed y 5 / 6 class, attainment ranging from 2A to 6B. Have you any ideas for mental / oral or starter activities and how I could organise them? I am not a specialist!
Look at the BEAM We Can Do It books. In my experience, children who are weak at number work (and therefore lower NC levels) are often better than the most able at problem solving as finding it difficult comes naturally to them! More able children can find it hard to cope with the answer not being obvious. At the start of the We Can Do It books there is a list of problem solving techniques - I have these on cards on display in the classroom, and at the start of a problem solving lesson we discuss which of the techniques will be used to solve today's problem. I'd just use any normal mental/oral starter activity, unless the day's problem requires specific shape knowledge, for example, which I might then revise in the starter.
In terms of organisation I'd put them in mixed ability groups. With that ability spread you might want to have 2 different levels of problems running ie something for your levels 2-4 and something for the levels 4-6, but I'd then mix abilities within those groups.
Nrich Maths is brilliant for resources - you could do all your lessons from their website and never spend any money on books. If you do want to buy anything, then Tarquin press do some lovely (cheap) books - mathematical treasure hunts and mathematical team games are my 2 favourites.
How do you reconcile mixed ability grouping with adequate differentiation? We are expecting OfSTED this year and MUST DO EVERYTHING RIGHT. (Although we know that under the new OfSTED we will certainly be found inadequate. )