Measuring Lengths

In this lesson, you'll learn about using measurement units. 

Click 'start course' to begin this activity. Read each page and do the quiz questions. Use the 'next' button to go to the next page. 



Length is the distance from one point to another.

Also, we know length is involved when people ask questions such as:

How long is...?

How wide is...?

What is the height of...?

How tall are you?

How far is it to...?

Knowing about length is important to measure the size of stock yards, buildings, fences and distances between places. 


Measuring length, height or distance

Four of these pictures show measurements of length, height or distance.

Click on those four images then click submit when you're done. 


When you need to build something, you do a lot of measuring. Most of the time you use a tape measure. Measuring a piece of timber for cutting. 

Measuring the height of a wall frame.

Measuring the height of a wall frame.

Measuring the length of a piece of timber.

Measuring the length of a piece of timber.




Match the words with the right sentence

Look at these words, match them to the correct sentence for the same measurement
  • Height
    Jason was very tall.
  • Length
    The yard fences are 18 metres long.
  • Distance
    The cattle truck has to travel 380km today.

Symbols for measuring

Units of measurement

The units used to measure things are listed here from smallest to biggest, are

                    Millimetres = mm                    Centimetres = cm

                    Metres = m

                    Kilometres = km

You will use different units for measuring different things.

The smallest unit is mm and the largest is km. 

Order the symbols

  • mm, cm, m, km
  • cm, mm, m, km
  • km, mm, m, cm
  • mm, cm, km, m
Choose the answer that shows the symbols in correct order from smallest unit to largest unit. 

match words to symbols

  • Centimetres
  • metres
  • millimetres
  • kilometres

Match sentences

Match these sentences with the correct measurement words
  • Mary is 160cm tall.
    This is measured in centimetres.
  • Chandra threw the ball 3m.
    This is measured in metres.
  • There is a 100km drive from Cairns to Innisfail.
    This is measured in kilometres.
  • The timber needed to be cut 5mm.
    This is measured in milliimetres.

mm and cm

You can choose to measure length in any of these four units depending on what you're measuring. 

Large areas are measured in metres or kilometres e.g. a room, a cattle yard or the length of the property. 

Smaller areas are measured in cm or mm e.g. a piece of timber , the size of a nail or a screw, or your height. 

cm and mm

Click on two things that would be measured in cm or mm.

m and km

Click on two things that would be measured in m and km.

Estimate how long this person's step is

  • 1 metre
  • 1 millimetre
  • 1 centimetre
  • 1 kilometre

Estimate how thick this fingernail is

Photo of the thickness of a person's fingernail.

  • 1 metre
  • 1 millimetre
  • 1 centimetre
  • 1 kilometre

Which items measure length and width

HINT: A speedo measures your speed, or how fast you are going. But is does not measure the distance you travelled. 

Click on three tools that are used to measure length or height. 

Activity Complete


This activity is now complete. Return to the course main page to continue your learning.