What is a Kilometre (km)?

S1-SA4-0432

Grade Level:

Class 3

Physics, Geography, Computing, GPS, AI, Transport

Definition

What is it?

A kilometre (km) is a unit used to measure long distances. It tells us how far one place is from another. One kilometre is equal to 1000 metres.

Simple Example

Quick Example

Imagine you are going from your home to your school. If your school is very far, we would measure that distance in kilometres. For example, your school might be 2 kilometres away from your house, meaning you would travel 2000 metres.

Worked Example

Step-by-Step

PROBLEM: An auto-rickshaw driver completed a ride of 5 kilometres. How many metres did he travel?

Step 1: Understand the relationship between kilometres and metres.
We know that 1 kilometre = 1000 metres.

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Step 2: Identify the given distance in kilometres.
The auto-rickshaw travelled 5 kilometres.

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Step 3: Multiply the distance in kilometres by 1000 to convert it to metres.
Distance in metres = 5 km * 1000 metres/km

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Step 4: Calculate the final value.
Distance in metres = 5000 metres.

ANSWER: The auto-rickshaw driver travelled 5000 metres.

Why It Matters

Understanding kilometres is vital for planning journeys, mapping locations, and even in sports. It's used by pilots, train drivers, and delivery persons every day. Knowing distances helps in fields like Geography for understanding land sizes and in GPS for navigating to new places.

Common Mistakes

MISTAKE: Thinking 1 kilometre is 100 metres. | CORRECTION: Remember that 1 kilometre is 1000 metres. The 'kilo' part means 'thousand'.

MISTAKE: Confusing kilometre with other units like metres or centimetres for long distances. | CORRECTION: Use kilometres specifically for measuring long distances, like the distance between cities or towns. Metres are for shorter distances, like the length of a room.

MISTAKE: Not writing 'km' after the number when talking about kilometres. | CORRECTION: Always use the abbreviation 'km' after the number to clearly show you are talking about kilometres, e.g., '10 km' not just '10'.

Practice Questions

Try It Yourself

QUESTION: If your friend's house is 3 km away, how many metres is that? | ANSWER: 3000 metres

QUESTION: A bus travels 10 kilometres from the bus stand to the market. Then it travels another 5 kilometres to the school. What is the total distance the bus travelled in kilometres? | ANSWER: 15 km

QUESTION: A car needs to travel 25 kilometres. It has already covered 12 kilometres. How many more metres does it need to travel? | ANSWER: 13000 metres

MCQ

Quick Quiz

Which of the following is the best unit to measure the distance from Mumbai to Delhi?

Centimetres

Metres

Kilometres

Millimetres

The Correct Answer Is:

Kilometres are used for measuring very long distances, like between two cities. Metres, centimetres, and millimetres are too small for such a large distance.

Real World Connection

In the Real World

When you book a cab or an auto-rickshaw using apps like Ola or Uber, the app calculates the fare based on the distance travelled in kilometres. Even when checking the distance to a new restaurant on Google Maps, you'll see it displayed in kilometres, helping you estimate travel time.

Key Vocabulary

Key Terms

UNIT: A standard amount used for measurement | DISTANCE: The space between two points | METRE: A basic unit of length; 1000 metres make 1 kilometre | KILOMETRE: A unit of length equal to 1000 metres, used for long distances | MEASUREMENT: The process of finding the size or amount of something

What's Next

What to Learn Next

Now that you understand what a kilometre is, you can learn about other units of measurement like metres and centimetres. You'll then be able to easily convert between these units and solve more complex problems involving distances.