## Thursday, 25 October 2012

### Working with 3D Shapes

I love the way you can go to your PLN and ask for help and ideas.

And I love being able to help when someone else puts out the call.

So when I got a message the other day from a Twitter follower asking for ideas for promoting inquiry into 3D shapes with a Year 2 class, I was happy to help.

Here's the ideas I came up with. You can probably think of others that you might suggest in the comments section below...

1. I like to refer to 3D shapes as "real"shapes - they exist in reality. Unlike 2D shapes which only exist in the imaginations of geometrists. 2D shapes are not real - they cannot exist in the 3D world. We can see representations of them but everything "real" has depth.

2. Get out some paper shapes - circles, squares, triangles etc to see what shapes the kids can make using flat shapes as faces. And what about if they curve the flat shape, like to make a cylinder? What shapes can't they make? (Have a chat with Mr Mercator about the sphere..) Continue the discussion about nets and how to assemble a 3D shape from a net.

3. Get some solids and paint the faces then print onto white paper. Reassemble a copy of the original solid from the net formed. Try with a sphere haha!

4. Use playdough to make 3D shapes - very tactile and great for kinesthetic kids. Make sure sides and angles are straight with a ruler or flat edge.

5. Do cross sections of prisms etc by cutting playdough with plastic knife of pulling apart the stack made in 4 (above).

6. Use plastic shapes, squares, triangles, circles etc, to make a stack of similar shapes to create a prism - a shape projected through itself. What happens when you lift up half of the stack? What shape do you see in the cross-section?

7. Get kids to group a set 3D shapes - what properties do they have in common? What characteristics can be used to classify them - prisms, pyramids, curved faces etc.

There are lots of ways to explore and investigate 3D shapes. The most important thing is to actually make physical contact with a few of them, not just look at pictures in a textbook.

Have some fun.

Here's some suggestions that have come through so far:

Suggestion 1: Imagine you live inside a 3D shape. Design the interior. Next, perform a mime for the class about living in that shape. Class guesses what shape you are living in.

Suggestion 2: I love the feely box activity! Hide a 3D shape inside a box with holes in the side so a student can insert their hands and feel the shape. The class ask the student questions to try and guess the shape. The child with the box needs to feel the shape in order to answer the questions. Its great to do a number of times to develop the children's questions and also the terminology they use. ie Does the shape have more than one right angle? What makes a good question? discussions are good too.