An icosahedron has 20 faces 

Room 13 have been very busy bees making 3D shapes out of brightly coloured paper and attaching thread to put on the class Christmas tree. The official name of a 3D shape is polyhedron which means a shape with many faces - and the diamonds we've been creating have 8 faces - an octahedron is the correct name.

We've also been making 3D shapes out of play dough and toothpicks. We counted the edges, vertices and faces of each of the shapes we made and recorded our results in a chart in our maths book. Someone in our class figured out that the vertices are the number of play dough blobs in your shape and the edges are the number of toothpicks in your shape (but you still have to count out your shape's faces). It was really fun to make the shapes, especially an icosahedron (picture on left).

Here's what some students thought bout making the shapes:

"I liked making the play dough creations because you could make up your own shapes and be inventive" - Max

"Making the shapes was quite fun" - Sasha

Our Christmas tree isn't completely decorated but some of our diamonds are on the tree (as pictured). Everyone loves the bright colours on the tree and hope to make more decorations so our tree looks great. Do you have any ideas for decorations?

By Georgie