This activity is suitable for the able pupils from Key stage 1 upwards. I find that because the activity uses only a small amount of knowledge and skill there is spare resources in pupils' brains to think at the same time about ways of trying to make sure that all the ways of rolling the three dice are reached. There can be interesting discussion about whether 6 5 4 is the same as 4 5 6. When considering combinations that pupils are often required to sort out I find that this activity is a good one to start with once they have had a go at practical ones. If you are doing this with an ordinary class then year 5's certainly find it a good challenge. It opens many doors for the children to consider what happens when you subtract a higher number from a lower one. When working with a class of year 4's towards the end of the academic year I found that some pupils simply said that you could not take 5 from three. Others said you get nothing [zero] and a few said that you need 2 more to be able to do it. Many already realised it would be minus 2. Whatever groups you do this with I would be interested to have feedback, particularly if you allow freedom in the way that they record the investigation, and what extensions they devise.