Cubes, Cuboids, Cylinders and Spheres for Primary 1

Three dimensional shapes

Performance Objectives

By the end of the lesson, students should be able to:

1. sort out cubes, cuboids, cylinders and spheres;
2. identify and name cuboids, cubes, cylinders and spheres;
3. distinguish between cuboids and cubes;
4. mention solid shapes in homes and environment.

What Are Three-Dimensional Shapes?

A three-dimensional shape is a solid object that takes up space. These shapes are not flat like drawings on paper; they have length, width, and height.

Imagine holding a ball or a box. These are examples of three-dimensional shapes because they are solid and you can feel their different sides and curves.

Cubes

A cube is a three-dimensional shape that looks like a box with all its sides being squares. All the flat surfaces of a cube are the same size.

Common objects that are cubes include a Ludo dice and some sugar cubes.

Cuboids

A cuboid is a three-dimensional shape that also looks like a box, but its sides can be different sizes. Some of its flat surfaces are rectangles.

Objects that are cuboids include matchboxes, empty packets of sugar, and shoeboxes.

Distinguishing Between Cuboids and Cubes

Cubes and cuboids both have flat sides, but they are different. The main difference is in the shape of their flat surfaces.

1. A cube has all its flat surfaces shaped like squares, and all these squares are the same size.
2. A cuboid has flat surfaces that are mostly rectangles. Some of its flat surfaces can be squares, but not all of them are the same size.

Think of a Ludo dice (cube) and a matchbox (cuboid). The Ludo dice has all square sides, while the matchbox has rectangular sides.

Cylinders

A cylinder is a three-dimensional shape that has two flat circular ends and one curved side. It looks like a can or a pipe.

Examples of objects that are cylinders include empty tins of Milo, empty tins of milk, and soft drink cans.

Spheres

A sphere is a perfectly round three-dimensional shape. It has no flat sides or corners, only a curved surface.

Objects that are spheres include footballs, tennis balls, and marbles.

Identifying and Naming Three-Dimensional Shapes

Identifying a shape means knowing its name when you see it. Naming a shape means saying its correct name.

When you see a Ludo dice, you can identify it as a cube. When you see a football, you can identify it as a sphere.

Sorting Three-Dimensional Shapes

Sorting shapes means putting similar shapes together in groups. This helps to organise objects based on their appearance.

How to Sort Shapes

The procedure for sorting shapes involves the following steps:

1. Gather different three-dimensional objects, such as a Ludo dice, a matchbox, an empty Milo tin, and a ball.
2. Look carefully at each object and decide if it is a cube, cuboid, cylinder, or sphere.
3. Place all the cubes in one group.
4. Place all the cuboids in another group.
5. Place all the cylinders in a third group.
6. Place all the spheres in a fourth group.
7. Check each group to make sure all the shapes in it are the same type.

Solid Shapes in the Home and Environment

Many objects around the home and in the environment are three-dimensional shapes. Recognising these shapes helps to understand the world around us.

Examples of solid shapes found in homes and the environment include:

1. Cubes: Ludo dice, some small gift boxes.
2. Cuboids: Matchboxes, shoeboxes, empty cereal boxes, building bricks, refrigerators.
3. Cylinders: Empty tins of milk, soft drink cans, water bottles, tree trunks, drums.
4. Spheres: Footballs, oranges, marbles, globes.