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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

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x-2y+3z=-3 2x-y+z=7 -x+3y-z=6
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Need help solving this problem (2/7)^-2
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lim x to infinity e^1-e^-1/log(1+x)
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12, 17, 22.... 25th term
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I'm 13 and I understand it great
I am 1 year old but I can do it! 1+1=2 proof very hard for me though.
Not really they are just easy concepts which can be understood if you have great basics. I am 14 I understood them easily.
find the 15th term of the geometric sequince whose first is 18 and last term of 387
Jerwin Reply
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The given of f(x=x-2. then what is the value of this f(3) 5f(x+1)
virgelyn Reply
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If f(x) = x-2 then, f(3) when 5f(x+1) 5((3-2)+1) 5(1+1) 5(2) 10
how do they get the third part x = (32)5/4
kinnecy Reply
make 5/4 into a mixed number, make that a decimal, and then multiply 32 by the decimal 5/4 turns out to be
can someone help me with some logarithmic and exponential equations.
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it think it's written 20/(X-6)^2 so it's 20 divided by X-6 squared
I'm not sure why it wrote it the other way
I got X =-6
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Commplementary angles
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A soccer field is a rectangle 130 meters wide and 110 meters long. The coach asks players to run from one corner to the other corner diagonally across. What is that distance, to the nearest tenths place.
Kimberly Reply
Jeannette has $5 and $10 bills in her wallet. The number of fives is three more than six times the number of tens. Let t represent the number of tens. Write an expression for the number of fives.
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What is the expressiin for seven less than four times the number of nickels
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why surface tension is zero at critical temperature
I think if critical temperature denote high temperature then a liquid stats boils that time the water stats to evaporate so some moles of h2o to up and due to high temp the bonding break they have low density so it can be a reason
Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
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. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
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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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