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Natural sciences

Grade 4

Planet earth and the universe

Module 40

The earth and its movement


Talking about the earth



  • This picture shows what the earth looks like from space. Space travellers tell us that the earth looks like a large, shining ball in the dark sky. It looks as if the surface of the earth is covered in clouds. The blue areas that we see are the oceans of our planet. The earth may seem small when we look at it from the moon, but if you had to dig through the middle of the earth to the other side, you would have to dig a tunnel of 6 400 km long!
  • The earth is the only planet on which life is possible, because it has a supply of air, water and soil. Only a quarter (approximately) of the earth’s surface is land, the rest is water in the form of the oceans, rivers, lakes, etc. The land consists of deserts, forests, grasslands, mountains and ice.

Divide the class into eight groups. You are going to make posters about this wonderful earth and put them up in the class. Use old magazines to make a collage on an A3 sheet of paper.

Group 1: Oceans

Oceans are made up of salt water and they cover a large part of the earth. Wind creates waves and keeps the water in motion all the time. The average depth of the ocean is 4 000 m. Plants and fish live even deep down in the sea.

Group 2: Deserts:

These are dry areas where it hardly ever rains. It is usually sandy, with rocks and stones here and there. There is very little water and therefore very few plants grow. The Sahara, in Africa, is the largest desert in the world.

Group 3: Polar Regions:

The Polar Regions are at the North and South Poles. They are covered in snow and ice and are the coldest places on earth.

Group 4: Grasslands:

These are relatively flat areas that receive very little rain. There are few trees, but many animals such as buck, zebras, giraffes, etc. live here. After rains have fallen there usually is much grass that can be eaten by the animals.

Group 5: Forests:

These are areas where trees grow very densely. Many animals and snakes and many types of birds and spiders are found in these forests.

Group 6: Rivers:

The longest river in the world is the Nile, which is approximately 6 671 km long. Rivers usually have their sources in mountains and may have waterfalls. Rivers usually have fresh water, sometimes fish are found in them and towns and factories are often developed alongside them. Rivers usually end at the sea and often form deltas where the river flows into the sea. Can you explain what a delta is?

Group 7: Mountains:

The highest mountain in the world is Mount Everest, which is 8 848 metres high. It is very cold on the highest peaks of such high mountains.

Group 8:Plant and animal life:

We find plants and animals everywhere on earth.


Investigating and describing the movement of the earth

[lo 1.3, 2.1]

What causes day and night?

Use a ball and paste a map of South Africa on it. This ball represents the earth. You could also use a real globe. Use a torch to represent the sun. Spin the ‘earth’ to demonstrate the change from day to night. One full turn takes 24 hours (1 day). At the same time move the ‘earth’ around the ‘sun’ to demonstrate how the seasons come about. This takes 365¼ days (1 year).

Use the following key words to describe how day and night occur. Write a paragraph on the lines that are provided:

Key words: earth, spin, 24 hours, axis, sun, day, night


LEARNING OUTCOME 1: SCIENTIFIC INVESTIGATIONSThe learner will be able to act confidently on curiosity about natural phenomena, and to investigate relationships and solve problems in scientific, technological and environmental contexts.

Assessment Standard

We know this when the learner

  • leads investigations and collects data.

1.3 evaluates data and provides feedback on observations.

LEARNING OUTCOME 2 : CONSTRUCTING SCIENCE KNOWLEDGE The learner will know and be able to interpret and apply scientific, technological and environmental knowledge.

Assessment Standard

We know this when the learner

2.1 recalls significant information.


This is a very pleasurable activity where learners learn to work together and to look at magazines with enquiring minds in order to find the right pictures for their collages. These can look beautiful in class or in a corridor.

Earth's movement

  • How do day and night happen?

Use the following key words to describe how day and night happen. Write a paragraph on the following lines:

Key words : earth, revolves, 24 hours, axis, sun, day, night

The earth revolves around its own axis every 24 hours . When any part of the earth faces the sun , it is day ; when it faces away from the sun , it is night .

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Natural sciences grade 4. OpenStax CNX. Sep 18, 2009 Download for free at http://cnx.org/content/col11096/1.1
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