Topic: What shape does the Earth have?

Supplementary material for use in lessons in the group of natural sciences (nature, biology, chemistry, geography, physics), additional classes, science clubs. It can serve as a resource for expanding knowledge, preparing students for science competitions.

Target group

5th‑grade students of elementary school

Core curriculum

Grade V Geography
II. Skills and application of knowledge in practice.

1) Conducting observations and measurements in the field, analyzing the obtained data and formulating conclusions based on them.

General aim of education

Students describe the shape and size of the Earth.

Key competences

• communication in foreign languages;

• digital competence;

• learning to learn.

Criteria for success
The student will learn:

• indicate observations that allow you to determine the shape of the Earth;

• determine the shape and size of the Earth.

Methods/techniques

• expository

  • talk.

• activating

  • discussion.

• programmed

  • with computer;

  • with e‑textbook.

• practical

  • exercices concerned.

Forms of work

• individual activity;

• activity in pairs;

• activity in groups;

• collective activity.

Teaching aids

• e‑textbook;

• notebook and crayons/felt‑tip pens;

• interactive whiteboard, tablets/computers;

• globes;

• styrofoam balls (as large as possible) cut in half, colored ribbons, markers, cards, pins.

Lesson plan overview

Before classes

• Students get acquainted with the content of the abstract. They prepare to work on the lesson in such a way to be able to summarize the material read in their own words and solve the tasks themselves.

Introduction

• The teacher gives the topic, the goals of the lesson in a language understandable for the student, and the criteria of success.

Realization

• Students perform Task 1. The teacher instructs the students to write a research question and a hypothesis in the form provided in the abstract. Then the students record their observations and conclusions. The teacher points the person who shares his insights and explains the conclusions made..

• The teacher asks students to read the given fragment of the abstract and try to remember its content. Then the participants, working in pairs, ask each other about the knowledge of the fragment.

• Students perform exercises and commands. The teacher checks and supplements the answers, providing students with the necessary information. Provides feedback..

• The students are paired up. Each pair receives: Styrofoam balls (as large as possible) cut in half, colored ribbons, markers, cards, pins and using materials presents the dimensions of the Earth: perimeter, diameter and radius. Students demonstrate the effects of their work, choose the best models by voting.

• Each pair of students receives a globe, and the teacher asks students to give examples of how to use the globe in science. He writes ideas on the board. Together with students, they choose three, which students write in a notebook.

Summary

• The teacher displays the criteria for success and asks the students to assess their skills acquired during the classes.

Homework

• Listen to the abstract recording at home. Pay attention to pronunciation, accent and intonation. Learn to pronounce the words learned during the lesson.

The following terms and recordings will be used during this lesson

Terms

Texts and recordings

What shape does the Earth have?

An ant climbing a tree trunk is unable to describe its shape or size. A man standing on the surface of the Earth finds himself in a similar situation. However, today there are no doubts about the size and shape of the Earth. How do we know that?

The size of a human being is so small in comparison with the whole Earth that we cannot fathom its shape or dimensions. Our ancestors thought that it was flat. It was not until a number of studies demonstrated that the Earth was spherical. It was finally proven by voyages around the world. Space flights provided us with photographs which make it possible to precisely determine the shape of the Earth.

Of course, we do not have to fly into space to convince ourselves that the Earth is round. The evidence for the spherical shape of our planet includes:

• the area encircled by the horizon (apparent line that separates earth from sky) has a circular shape, which increases with increasing height above the ground,

• observation of the shadow of the Earth during the lunar eclipses, when the Moon passes directly behind Earth and into its shadow,

• observations of ships approaching the port.

We already know how to prove that the Earth is spherical. And how can we find out what size it is? The size of the Earth can be calculated by making precise measurements. Already in antiquity, scholars noticed that the Sun observed in one location is higher above the horizon than in another location further to the north. By making very accurate measurements of sun‑ray angles, they calculated that the circumference of the Earth was about 40 000 km. Today we know that the Earth's circumference is 40 075 km, and the average radius – is about 6371 km. This means that its diameter is approximately 12 742 km.

Due to its enormous dimensions, we cannot see the entire Earth. Therefore, a model was created which shows the Earth in a much diminished form. We call it a globe. The globe is indispensable in any life sciences classroom. It shows not only the shape of the Earth – but also where land masses and oceans are.

Precise measurements and observations have shown that the Earth is not exactly a sphere. The movement around its own axis creates a centrifugal force. As a result, the Earth is slightly flattened. Such a flattened sphere is called an ellipsoid.

• Because of its size, the Earth seems flat to an observer standing on its surface.

• Observations prove that the Earth has a spherical shape.

• The circumference of the Earth is approximately 40 000 km and its diameter is 12742 km.