☰ Year plan · Mathematics

3D shapes (2)

Week 20 · Unit 10 · 10.1 · 4 lessons
1

Meet the 3D shapes

Learner’s Book 1: Unit 10, pp. 139–141
GoalName cubes, cuboids, pyramids, cylinders and spheres, and sort them by their surfaces.
New words
3D shape · a solid shape that takes up spacecuboid · a shape like a box, with 6 flat facespyramid · a shape with a flat base and sloping triangle sides that lean in to a point
Explanation

3D shapes are solid. You can pick them up and hold them. A cube is like a dice: all of its 6 flat faces are squares. A cuboid is like a box and also has 6 flat faces. A cylinder is like a tin: it has a circle at each end and a curved side all the way round. A sphere is round all over, like a ball. A pyramid stands on a flat base, and its sloping triangle sides lean in to a point.

cubecuboidpyramidcylindersphere
diceshoe boxpyramid tenttin canball
Worked examples
A shoe box is a cuboid. It has 6 flat faces, and all of them are rectangles.
The roof of a pyramid tent is a pyramid. It stands on a flat base, and its triangle sides lean in to a point.
can rollcannot roll
ball, tindice, box, tent
We can sort shapes by whether they roll. A ball and a tin can roll. A dice, a box and a toy tent cannot roll, because they have only flat faces.
Class activity

Shape treasure hunt: find a cube, a cuboid, a cylinder, a sphere and a pyramid at home or in class (a dice, a cereal box, a tin, a ball, a toy tent). Put them on a tray. Which ones have a curved surface? Which have only flat faces?

Practice
1
What is the name of this shape?
2
What is the name of this shape?
3
A cylinder has flat faces. Does it also have a curved surface?
4
Sort these things: an orange, a book, a drum, a brick. Which ones have a curved surface?