The objective of this unit is to introduce young learners to the concept of categorising objects according to their shape and structure. Pupils are introduced to simple 2D and 3D shapes and the vocabulary to describe their properties: flat, solid, straight, curved, edge, corner, face.

The unit begins with common 2D shapes - circles, triangles, squares, rectangles - and differentiates between curved and straight edges. 3D shapes are introduced through everyday objects - a tin of beans, an ice-cream cone, a box of cereal, a die - which are then transformed into mathematical models.

There are activities to identify shapes among mathematical models and everyday objects, including differentiating between pyramids and prisms. Activities can be done individually, in pairs or in small groups. If pupils work in pairs or groups, ask them to explain their reasoning to their partners and to agree on selections before moving on.

There are inherent perceptual difficulties in dealing with 3D shapes in a 2D medium. The materials attempt to overcome this by using images of everyday objects which are likely to be familiar, but teachers need to be aware that some children will still be confused by the shape of faces in a 2D representation of a 3D object, so you are advised to provide real shapes and objects that the children can handle alongside the unit.

Extension

• This unit contributes to the development of understanding categorisation, but it also links to the mathematics curriculum - shape and space. The unit can be followed by a variety of practical activities done in pairs or small groups.
• Sort mathematical models into flat shapes and solid shapes.
• Investigate which 3D shapes roll - and how - and which ones don't.
• Sort a collection of 2D shapes into groups according to their shape (using a mix of sizes and colours).
• Sort a collection of 3D shapes into groups according to their shape (using a mix of sizes and colours).
• Get one person to describe a shape. The rest of the group has to guess what the shape is.
• Investigate how different shapes tessellate.
• Provide puzzles based on shapes.