3.1 Visualise and name 3-dimensional objects in the environment  (Page 46/2)

Mathematics

Grade 4

Measurement, space and shape

Module 11

Visualise and name 3-dimensional objects in the environment

Activity 1:

To recognise, visualise and name 3-dimensional objects in the environment [LO 3.1]

To describe, sort and compare them [LO 3.2]

Prisms, rectangular prisms, spheres, cylinders, pyramids, and other objects are found all round us.

1. Study the following three-dimensional objects in order to learn their names and be able to recognize and name similar objects in the world around us:

2. Objects in the world around us: now try to draw and name the 3-D objects:

3. More shapes and objects.

3.1 Write each of the following solid objects under the correct geometrical heading: The sun; a string of spaghetti; a block of ice; an ordinary candle; the handle of a garden rake; a book; an orange; a brick; a block of margarine. Think of others and write them in the columns too, especially the columns that seem to be rather empty.

3.2 Compare your lists with those of your friends. If they have an item that you have not thought of, you may add it to your list.

. Write the correct geometrical name next to each of the following:

• a block of flats
• the walls of a rondavel
• a wigwam/tepee
• the roof of a rondavel
• the stones at Stonehenge

5. Look at the objects again. How many surfaces are there? Are the surfaces flat or curved? What shape are the surfaces? Fill in the missing words to describe the objects:

Activity 2:

• To recognise, visualise and name 2-D shapes and 3-D objects in the environment [LO 3.1]

• To describe, sort and compare 2-D shapes and 3-D objects from the environment [LO 3.2]

• To make 2-D shapes, 3-D objects and patterns from tangrams [LO 3.5]

• Two-dimensional shapes are flat. We can draw them on a piece of paper . Polygons are all closed geometric shapes with straight sides.

1. Polygons : Use your pencil and ruler to practise drawing these.

3 sides: Triangles

4 sides: Quadrilaterals

5 sides: Pentagons (when all the sides are equal in length, it is a regular pentagon; if they are different lengths, it is an irregular pentagon)

6 sides: Hexagons

7 sides: Heptagons

(Try to draw one regular heptagon.)

2. Circles

2.1 Circles are not polygons. Look at the circle below and compare it with the polygons that we have discussed:

• Complete: The circle is not a polygon because __________________________
• Now try to think of an example of each shape that we have considered, in your environment. Remember, they must all be flat because they are two-dimensional. In each shape below, fill in the road signs that you have seen in the world around you and on the way to school.

3.1 The Circle

3.2 The Triangle

3.3 The Square

3.4 The Rectangle

3.5 The Octogon

4. Cut out the TANGRAM on the next page. Cut out all the shapes in it.