Why do this problem?
is very good for introducing the concept of surface area. Being very practical it helps pupils to understand the ideas before looking at any kind of formulae. It also widens the pupils' experiences of nets.
I would recommend that the activity is presented to the whole class as suggested with ideas explored together before the pupils go to explore on their own or in twos.
Tell me about your shape.
Have you checked to see if your paper shape works? (it's good to ask this even when you can see it's a good one!)
Children can alter the shape of the present, for example, a kind of cuboid shape with a hole down the middle or a cylinder.
There may be a need for help with the pupils with fine motor skill problems.