3D Objects — South Australian Year 3 Maths
Naming cubes, prisms, pyramids, cylinders, cones and spheres, matching them to everyday objects, and counting faces, edges and vertices. Two subtopics and 40 practice questions, aligned to AC9M3SP01.
3D Objects in South Australian Year 3
3D objects are solid shapes that take up space, such as boxes, balls and cans. In this topic students name the common solids, link them to everyday things and describe them by their faces, edges and vertices, including the curved surfaces of cylinders, cones and spheres.
The two subtopics below are Identify and name 3D objects and Describe features (faces, edges, vertices). 3D Objects is one of the 18 topics in South Australian Year 3 Maths and belongs to the Space strand. Both subtopics come under Australian Curriculum code AC9M3SP01. These skills lead on to building and drawing 3D objects in later years.
Subtopics
3D Objects: common questions
What are faces, edges and vertices?
A face is a flat surface, an edge is where two faces meet and a vertex is a corner where edges meet. On a tissue box, the top is a face, the line along the top of a side is an edge, and each corner is a vertex.
How can my child remember the names of 3D objects?
Link each one to something at home: a dice for a cube, a cereal box for a rectangular prism, a tin of soup for a cylinder, an ice-cream cone for a cone and an orange for a sphere. A pyramid comes to a point, while a prism has two matching ends.
How do you count the edges of a solid without missing any?
Count in groups. A hexagonal prism, like some pencils, has 6 edges around each end and 6 joining the ends, so \(6 + 6 + 6 = 18\) edges. Marking each edge with a sticker as you count also helps.
What mistakes do children make with 3D objects?
They may count the curved surface of a cylinder as a flat face, call a cube a square or a ball a circle, or count the same edge twice. At home, collect boxes and tins, sort them by whether they roll, stack or slide, and count their faces together.
Which curriculum codes cover 3D Objects in South Australian Year 3?
Both subtopics come under Australian Curriculum v9 code AC9M3SP01, which is about comparing and sorting objects by their main features.