3D Shapes

Having learned all about the properties of 2D shapes, the students excitedly started the week wanting to show me all they knew about 3D shapes. So I set up a provocation by showing them a cube and asking them to tell me everything they knew about it.

As you can see, the students were quite familiar with cubes. Mr V. Also added:

“A cube is relate to a rectangular prism”

I often forget they are only 6 years old! Although they didn’t know the word ‘net’, they certainly knew that when you unfolded a cube, it looked like a hopscotch game! So they got another word added to their “Shape vocabulary” wall.



As a way to further engaging the students, I printed out the nets of 11 different 3d shapes, and asked them to look at the nets through their ipad using the app “iClass Shapes” by HKU e-Learning Technology Development Laboratory. This is an augmented reality app which converts the nets into their 3D shapes.

The students were mesmerised by the “magic” of the app.

Before they were sent off to play with the shapes, I posed these two questions:

Armed with the knowledge of their goal for the lesson, the students took off and started exploring the properties of 3D shapes.

Looking at a hexagonal prism through iClass Shapes

Using the buttons on the side of the screen, the students can rotate the shape along the x, y or z axis.

After their exploration, the students came up with these observations regarding the 3D shapes:

The faces of prisms are rectangular, and the faces of pyramids are triangular.

Mr F.

Prisms have flat tops.

Miss. E.

Pyramids have 1 vertex at the top.

Mr F.

As with the 2D shapes, I wanted the students to really understand how the shapes are are, so we constructed a variety of 3D shapes using jelly beans and toothpicks. As the students told me, the jelly beans represented the vertices and the toothpicks represented the edges. (On a quick side note, jelly beans are not the best to use, as little fingers make them warm and gooey, so the toothpicks can’t hold their shape for long!)

I sent students some 3D shape posters on their iPads, so they could reference them as they were building their shapes. Many students began with a cube, but once they were confident with their abilities, some students told me they wants to challenge themselves. I love hearing that!

Using the iPad as a resource.

The hexagonal prism was one of the more challenging models to make.

Some students ended up adding extra toothpicks to create supports for their structure as the jelly beans didn't hold to well.

Triangular prisms were popular and led the students to a wonderful realisationat the end of the end of the lesson.

Each student had their own process of constructing the shapes.

Look at my cube crown Mr. Cantone! (Mr. E)

A rectangular pyramid on top of a cube makes a house.

At the end of the session, when the students were asked to reflect on what they had learnt abt 3D shapes this week, they shared some lovely understandings.


There are many different types of 3D shapes.

Mr F.

3D shapes can be hard to make because there are lots of edges and vertices.

Mr W. & Miss L.

3D shapes have more vertices than 2D shapes.

Miss Z.

We then discussed the difficulties of making the shapes with the jelly beans. The students all agreed that the marshmallows they used to make their 2D shapes were much better than the jellybeans. However their discussion led them to realise that all their pyramid shapes held up much better than their prisms. Miss M. then came up with this reflection:

Triangular shapes are stronger than square shapes.

Miss M.

I loved that observation, and even though we really had to pack up and get ready for home time, I couldn’t let it go. So I briefly discussed the strength of triangles versus cubes and showed them some pictures of objects which utilise the strength and stability of triangles in their construction.

We looked at the use of triangles in bridges.

We discussed the stability a triangle offers bikes.

I really had lots of fun with this unit, and I hope the students did too. From our discussions I can certain tell they learnt a lot.











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