## Monday, 21 December 2009

### Polydron 3D Shapes

During the last few weeks, when we have been busy with our Christmas play, I needed an exciting maths project to keep the children focused during lessons. Earlier in the year we purchased Polydron apparatus for exploring 3D shapes.

I decided that I would use this as part of our study of 3D shapes.

We used the prisms and pyramids packs to explore the properties of these shapes. This created lots of discussion about edges, faces and vertices. It was fun to predict this for different prisms and pyramids.

We then used Polydron squares to find the eleven faces of a cube. Only one group found all eleven! In the past, this activity was done using card which the children had to draw their nets on and then test the shape. Using Polydron was so much quicker. We also had time to find the eleven nets of an octahedron in the same way.

We then talked about which 3D shapes could be considered to be 'regular'. These shapes are called 'platonic'. They are tetrahedrons, octahedrons and icosahedrons which all use triangles; cubes (squares) and the dodecahedron (pentagon). Each shape was described with the number of faces which meet at each vertice. Once each one had been designed, we explored the different nets of these shapes.

We also spend some time exploring archimedean solids - solids which are made up of faces of different shapes. Each shape was described using notation like 3.8.8 which meant a triangle, octagon and another octagon meet at each vertice. We had great fun building all sorts of different shapes. We had chance to explore the difference between a dodecahedron, an icosidodecahedron a rhombicosidodecahedron and a truncated dodecahedron. We find out what it means to truncate a shape.

The work was lots of fun and did keep the children focused. They learned about being systematic when it comes to investigating - and the equipment allows them to work more quickly. They learned the properties of the shapes. They considered how to modify the shapes.

The Polydron packs that we used were the Prisms, Pyramids and Archimedean Solids. They aren't very cheap at all, but if you interested, they are available here.

Pictures of our work can be found on our Year Six blog here.