Hello Woostarite, The challenge wall is a good idea and it is worth testing out to see what works and what doesn't work. Your mentors may be on board and want to help out (there may also be someone who already coordinates UKMT challenges at the school). Sorry for not quoting everyone else, but I do agree that problems shouldn't be restricted to certain year groups as there may well be someone in a year 11 set 3 who loves maths but can only access the year 9 problems (perhaps!). The use of the difficulty indicator with stars would work well here on its own I think (without specifying year groups). With regards to the actual 'listening to the solved problems' this could take up valuable 'personal' time that you need (breaks), so maybe you could enlist the help of some prefects/volunteers/6th form pupils to help with this - helps them out too with additional experiences. Our sixth formers take the IB so they are required to 'collect hours'. I think something like this would work well with them (quite a few already volunteer to provide support to younger pupils with maths classwork/homework). I do also agree that you need to be careful as to where you concentrate your energies. The GTP/NQT years are demanding and therefore if you were to try this out in any spare time left over all the other planning, why not give it a go. I loved seeing the enthusiasm by my PGCE mentee in the spring term, but also made sure that the lesson planning and behaviour management were the priorities. I look forward to seeing you develop this over time!