3
Review: shapes and fractions
Learner’s Book 1: Units 2–3, pp. 36–55
GoalName 3D and 2D shapes, count sides and faces, and recognise halves.
New words
face · a flat or curved part of a 3D shapeside · a straight or curved edge of a flat shapeequal · exactly the same sizehalf · one of two equal parts
Explanation
You can pick up a 3D shape and turn it round. A cube has 6 flat faces. A cylinder has 2 flat faces and a curved surface. A sphere has one curved surface and no flat faces, so it rolls. 2D shapes are flat. A circle has one curved side. A square and a rectangle have 4 straight sides. A triangle has 3 straight sides. A half is one of two equal parts. Two halves of a shape put together make the whole shape.
Worked examples
A cube has 6 flat faces, so it can be stacked easily.
A cylinder has 2 flat faces and 1 curved surface. It can be stacked on its flat face, and it can roll on its curved surface.
This circle has 2 equal parts and 1 is coloured. Half of the circle is coloured.
Class activity
Shape hunt: find things at home or in class shaped like a cube, a sphere and a cylinder (a dice, a ball, a tin). Which ones roll? Which ones stack? Then fold a paper square in half and check that the two parts match.
Practice
1
What is the name of this 3D shape?
A cylinder.
2
How many sides does this shape have?
3 (it is a triangle).
3
Is this square cut in half?
No. The two parts are not equal.
4
Which shape has one curved side: a circle or a square?
A circle.