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Christmas Presents

Stage: 2 Challenge Level: Challenge Level:2 Challenge Level:2

Christmas Presents


It's time to be giving prezzies [presents] to friends. We usually wrap them up so that there is some fun in unwrapping them. Little baby brothers and sisters tend to like the unwrapping more than the present itself!

We should probably try to save paper, though, and use no more than is necessary. So let's do some wrapping up and never have one piece of paper overlapping another. Remembering this, let's have a look at a very practical challenge.

It would probably be good to use some of those cubes which fit together [multilink] that are around in most schools and put perhaps 27 of these together to make a cube [which in this case would be 3 by 3 by 3].

Prezzy1

 

This is just so that we can have a reasonable sized prezzie, maybe it's a box with an interesting game in it ... I don't know!

We are just concerned with its shape:-

Prezzy2a

 

We need to wrap it up, remembering that we can have no overlaps. One rule here is that the paper will be made up of squares the size of the faces of the cube.

So you may decide on something like this:-


You notice that I've used red paper that is red on both sides so that nothing changes if I turn it over.

You could of course find other shapes to use. Here are just two more:-


Now you find the rest!

Remember to avoid reflections or turning over!


Now for part two of this challenge. What happens if we make one of the sides of this cube a bit different so that it becomes a cuboid?

Prezzy3a


How many different shapes of paper can be used this time?

Try to find them all.


Now for the third part. What if the prezzie were different from a cube in two directions?

Prezzy4


Can you predict how many different shapes of wrapping paper there will be this time?


If you can't, then make them all - that's one sure way of finding out!

Well, good luck with this rather different challenge which only becomes an investigation when you now ask the question "I wonder what would happen if ...?''


Why do this problem?

This activity 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.

Possible approach

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.

Key questions

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!)

Possible extension

Children can alter the shape of the present, for example, a kind of cuboid shape with a hole down the middle or a cylinder.

Possible support

There may be a need for help with the pupils with fine motor skill problems.